diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index c065cd6..a8c8408 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -33,7 +33,6 @@
 
 import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
 import static com.android.net.module.util.NetworkStackConstants.RFC7421_PREFIX_LENGTH;
-import static com.android.networkstack.tethering.TetheringConfiguration.USE_SYNC_SM;
 import static com.android.networkstack.tethering.UpstreamNetworkState.isVcnInterface;
 import static com.android.networkstack.tethering.util.PrefixUtils.asIpPrefix;
 import static com.android.networkstack.tethering.util.TetheringMessageBase.BASE_IPSERVER;
@@ -316,6 +315,7 @@
 
     private final TetheringMetrics mTetheringMetrics;
     private final Handler mHandler;
+    private final boolean mIsSyncSM;
 
     // TODO: Add a dependency object to pass the data members or variables from the tethering
     // object. It helps to reduce the arguments of the constructor.
@@ -325,7 +325,7 @@
             @Nullable LateSdk<RoutingCoordinatorManager> routingCoordinator, Callback callback,
             TetheringConfiguration config, PrivateAddressCoordinator addressCoordinator,
             TetheringMetrics tetheringMetrics, Dependencies deps) {
-        super(ifaceName, USE_SYNC_SM ? null : handler.getLooper());
+        super(ifaceName, config.isSyncSM() ? null : handler.getLooper());
         mHandler = handler;
         mLog = log.forSubComponent(ifaceName);
         mNetd = netd;
@@ -338,6 +338,7 @@
         mLinkProperties = new LinkProperties();
         mUsingLegacyDhcp = config.useLegacyDhcpServer();
         mP2pLeasesSubnetPrefixLength = config.getP2pLeasesSubnetPrefixLength();
+        mIsSyncSM = config.isSyncSM();
         mPrivateAddressCoordinator = addressCoordinator;
         mDeps = deps;
         mTetheringMetrics = tetheringMetrics;
@@ -515,7 +516,7 @@
 
         private void handleError() {
             mLastError = TETHER_ERROR_DHCPSERVER_ERROR;
-            if (USE_SYNC_SM) {
+            if (mIsSyncSM) {
                 sendMessage(CMD_SERVICE_FAILED_TO_START, TETHER_ERROR_DHCPSERVER_ERROR);
             } else {
                 sendMessageAtFrontOfQueueToAsyncSM(CMD_SERVICE_FAILED_TO_START,
@@ -1170,7 +1171,7 @@
                 // in previous versions of the mainline module.
                 // TODO : remove sendMessageAtFrontOfQueueToAsyncSM after migrating to the Sync
                 // StateMachine.
-                if (USE_SYNC_SM) {
+                if (mIsSyncSM) {
                     sendSelfMessageToSyncSM(CMD_SERVICE_FAILED_TO_START, mLastError);
                 } else {
                     sendMessageAtFrontOfQueueToAsyncSM(CMD_SERVICE_FAILED_TO_START, mLastError);
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index 0678525..d09183a 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -132,15 +132,15 @@
 
     public static final String TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION =
             "tether_force_random_prefix_base_selection";
+
+    public static final String TETHER_ENABLE_SYNC_SM = "tether_enable_sync_sm";
+
     /**
      * Default value that used to periodic polls tether offload stats from tethering offload HAL
      * to make the data warnings work.
      */
     public static final int DEFAULT_TETHER_OFFLOAD_POLL_INTERVAL_MS = 5000;
 
-    /** A flag for using synchronous or asynchronous state machine. */
-    public static final boolean USE_SYNC_SM = false;
-
     public final String[] tetherableUsbRegexs;
     public final String[] tetherableWifiRegexs;
     public final String[] tetherableWigigRegexs;
@@ -174,6 +174,7 @@
 
     private final boolean mEnableWearTethering;
     private final boolean mRandomPrefixBase;
+    private final boolean mEnableSyncSm;
 
     private final int mUsbTetheringFunction;
     protected final ContentResolver mContentResolver;
@@ -292,6 +293,7 @@
         mEnableWearTethering = shouldEnableWearTethering(ctx);
 
         mRandomPrefixBase = mDeps.isFeatureEnabled(ctx, TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION);
+        mEnableSyncSm = mDeps.isFeatureEnabled(ctx, TETHER_ENABLE_SYNC_SM);
 
         configLog.log(toString());
     }
@@ -385,6 +387,10 @@
         return mRandomPrefixBase;
     }
 
+    public boolean isSyncSM() {
+        return mEnableSyncSm;
+    }
+
     /** Does the dumping.*/
     public void dump(PrintWriter pw) {
         pw.print("activeDataSubId: ");
@@ -438,6 +444,9 @@
 
         pw.print("mRandomPrefixBase: ");
         pw.println(mRandomPrefixBase);
+
+        pw.print("mEnableSyncSm: ");
+        pw.println(mEnableSyncSm);
     }
 
     /** Returns the string representation of this object.*/
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
index aa322dc..19c6e5a 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
@@ -754,4 +754,26 @@
                 new TetheringConfiguration(mMockContext, mLog, INVALID_SUBSCRIPTION_ID, mDeps);
         assertEquals(p2pLeasesSubnetPrefixLength, p2pCfg.getP2pLeasesSubnetPrefixLength());
     }
+
+    private void setTetherEnableSyncSMFlagEnabled(Boolean enabled) {
+        mDeps.setFeatureEnabled(TetheringConfiguration.TETHER_ENABLE_SYNC_SM, enabled);
+    }
+
+    private void assertEnableSyncSMIs(boolean value) {
+        assertEquals(value, new TetheringConfiguration(
+                mMockContext, mLog, INVALID_SUBSCRIPTION_ID, mDeps).isSyncSM());
+    }
+
+    @Test
+    public void testEnableSyncSMFlag() throws Exception {
+        // Test default disabled
+        setTetherEnableSyncSMFlagEnabled(null);
+        assertEnableSyncSMIs(false);
+
+        setTetherEnableSyncSMFlagEnabled(true);
+        assertEnableSyncSMIs(true);
+
+        setTetherEnableSyncSMFlagEnabled(false);
+        assertEnableSyncSMIs(false);
+    }
 }
diff --git a/nearby/service/java/com/android/server/nearby/presence/EncryptionInfo.java b/nearby/service/java/com/android/server/nearby/presence/EncryptionInfo.java
index 1f9f70b..ac1e18f 100644
--- a/nearby/service/java/com/android/server/nearby/presence/EncryptionInfo.java
+++ b/nearby/service/java/com/android/server/nearby/presence/EncryptionInfo.java
@@ -17,11 +17,13 @@
 package com.android.server.nearby.presence;
 
 import android.annotation.IntDef;
+import android.annotation.Nullable;
 import android.nearby.DataElement;
 
 import androidx.annotation.NonNull;
 
 import com.android.internal.util.Preconditions;
+import com.android.server.nearby.util.ArrayUtils;
 
 import java.util.Arrays;
 
@@ -40,7 +42,7 @@
 
     // 1st byte : encryption scheme
     // 2nd to 17th bytes: salt
-    private static final int ENCRYPTION_INFO_LENGTH = 17;
+    public static final int ENCRYPTION_INFO_LENGTH = 17;
     private static final int ENCODING_SCHEME_MASK = 0b01111000;
     private static final int ENCODING_SCHEME_OFFSET = 3;
     @EncodingScheme
@@ -69,4 +71,20 @@
     public byte[] getSalt() {
         return mSalt;
     }
+
+    /** Combines the encoding scheme and salt to a byte array
+     * that represents an {@link EncryptionInfo}.
+     */
+    @Nullable
+    public static byte[] toByte(@EncodingScheme int encodingScheme, byte[] salt) {
+        if (ArrayUtils.isEmpty(salt)) {
+            return null;
+        }
+        if (salt.length != ENCRYPTION_INFO_LENGTH - 1) {
+            return null;
+        }
+        byte schemeByte =
+                (byte) ((encodingScheme << ENCODING_SCHEME_OFFSET) & ENCODING_SCHEME_MASK);
+        return ArrayUtils.append(schemeByte, salt);
+    }
 }
diff --git a/nearby/service/java/com/android/server/nearby/presence/ExtendedAdvertisement.java b/nearby/service/java/com/android/server/nearby/presence/ExtendedAdvertisement.java
index 34a7514..c2304cc 100644
--- a/nearby/service/java/com/android/server/nearby/presence/ExtendedAdvertisement.java
+++ b/nearby/service/java/com/android/server/nearby/presence/ExtendedAdvertisement.java
@@ -16,22 +16,27 @@
 
 package com.android.server.nearby.presence;
 
+import static android.nearby.BroadcastRequest.PRESENCE_VERSION_V1;
+
 import static com.android.server.nearby.NearbyService.TAG;
+import static com.android.server.nearby.presence.EncryptionInfo.ENCRYPTION_INFO_LENGTH;
+import static com.android.server.nearby.presence.PresenceConstants.PRESENCE_UUID_BYTES;
 
 import android.annotation.Nullable;
-import android.nearby.BroadcastRequest;
+import android.nearby.BroadcastRequest.BroadcastVersion;
 import android.nearby.DataElement;
+import android.nearby.DataElement.DataType;
 import android.nearby.PresenceBroadcastRequest;
 import android.nearby.PresenceCredential;
 import android.nearby.PublicCredential;
 import android.util.Log;
 
+import com.android.server.nearby.util.ArrayUtils;
 import com.android.server.nearby.util.encryption.Cryptor;
-import com.android.server.nearby.util.encryption.CryptorImpFake;
-import com.android.server.nearby.util.encryption.CryptorImpIdentityV1;
-import com.android.server.nearby.util.encryption.CryptorImpV1;
+import com.android.server.nearby.util.encryption.CryptorMicImp;
 
 import java.nio.ByteBuffer;
+import java.security.GeneralSecurityException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -51,37 +56,51 @@
  * The header contains:
  * version (3 bits) | 5 bit reserved for future use (RFU)
  */
-public class ExtendedAdvertisement extends Advertisement{
+public class ExtendedAdvertisement extends Advertisement {
 
     public static final int SALT_DATA_LENGTH = 2;
-
     static final int HEADER_LENGTH = 1;
 
     static final int IDENTITY_DATA_LENGTH = 16;
-
+    // Identity Index is always 2 .
+    // 0 is reserved, 1 is Salt or Credential Element.
+    private static final int CIPHER_START_INDEX = 2;
     private final List<DataElement> mDataElements;
+    private final byte[] mKeySeed;
 
-    private final byte[] mAuthenticityKey;
+    private final byte[] mData;
 
-    // All Data Elements including salt and identity.
-    // Each list item (byte array) is a Data Element (with its header).
-    private final List<byte[]> mCompleteDataElementsBytes;
-    // Signature generated from data elements.
-    private final byte[] mHmacTag;
+    private ExtendedAdvertisement(
+            @PresenceCredential.IdentityType int identityType,
+            byte[] identity,
+            byte[] salt,
+            byte[] keySeed,
+            List<Integer> actions,
+            List<DataElement> dataElements) {
+        this.mVersion = PRESENCE_VERSION_V1;
+        this.mIdentityType = identityType;
+        this.mIdentity = identity;
+        this.mSalt = salt;
+        this.mKeySeed = keySeed;
+        this.mDataElements = dataElements;
+        this.mActions = actions;
+        mData = toBytesInternal();
+    }
 
     /**
      * Creates an {@link ExtendedAdvertisement} from a Presence Broadcast Request.
+     *
      * @return {@link ExtendedAdvertisement} object. {@code null} when the request is illegal.
      */
     @Nullable
     public static ExtendedAdvertisement createFromRequest(PresenceBroadcastRequest request) {
-        if (request.getVersion() != BroadcastRequest.PRESENCE_VERSION_V1) {
+        if (request.getVersion() != PRESENCE_VERSION_V1) {
             Log.v(TAG, "ExtendedAdvertisement only supports V1 now.");
             return null;
         }
 
         byte[] salt = request.getSalt();
-        if (salt.length != SALT_DATA_LENGTH) {
+        if (salt.length != SALT_DATA_LENGTH && salt.length != ENCRYPTION_INFO_LENGTH - 1) {
             Log.v(TAG, "Salt does not match correct length");
             return null;
         }
@@ -94,12 +113,12 @@
         }
 
         List<Integer> actions = request.getActions();
-        if (actions.isEmpty()) {
-            Log.v(TAG, "ExtendedAdvertisement must contain at least one action");
-            return null;
-        }
-
         List<DataElement> dataElements = request.getExtendedProperties();
+        // DataElements should include actions.
+        for (int action : actions) {
+            dataElements.add(
+                    new DataElement(DataType.ACTION, new byte[]{(byte) action}));
+        }
         return new ExtendedAdvertisement(
                 request.getCredential().getIdentityType(),
                 identity,
@@ -109,149 +128,252 @@
                 dataElements);
     }
 
-    /** Serialize an {@link ExtendedAdvertisement} object into bytes with {@link DataElement}s */
-    @Nullable
-    public byte[] toBytes() {
-        ByteBuffer buffer = ByteBuffer.allocate(getLength());
-
-        // Header
-        buffer.put(ExtendedAdvertisementUtils.constructHeader(getVersion()));
-
-        // Salt
-        buffer.put(mCompleteDataElementsBytes.get(0));
-
-        // Identity
-        buffer.put(mCompleteDataElementsBytes.get(1));
-
-        List<Byte> rawDataBytes = new ArrayList<>();
-        // Data Elements (Already includes salt and identity)
-        for (int i = 2; i < mCompleteDataElementsBytes.size(); i++) {
-            byte[] dataElementBytes = mCompleteDataElementsBytes.get(i);
-            for (Byte b : dataElementBytes) {
-                rawDataBytes.add(b);
-            }
-        }
-
-        byte[] dataElements = new byte[rawDataBytes.size()];
-        for (int i = 0; i < rawDataBytes.size(); i++) {
-            dataElements[i] = rawDataBytes.get(i);
-        }
-
-        buffer.put(
-                getCryptor(/* encrypt= */ true).encrypt(dataElements, getSalt(), mAuthenticityKey));
-
-        buffer.put(mHmacTag);
-
-        return buffer.array();
-    }
-
-    /** Deserialize from bytes into an {@link ExtendedAdvertisement} object.
-     * {@code null} when there is something when parsing.
+    /**
+     * Deserialize from bytes into an {@link ExtendedAdvertisement} object.
+     * Return {@code null} when there is an error in parsing.
      */
     @Nullable
-    public static ExtendedAdvertisement fromBytes(byte[] bytes, PublicCredential publicCredential) {
-        @BroadcastRequest.BroadcastVersion
+    public static ExtendedAdvertisement fromBytes(byte[] bytes, PublicCredential sharedCredential) {
+        @BroadcastVersion
         int version = ExtendedAdvertisementUtils.getVersion(bytes);
-        if (version != PresenceBroadcastRequest.PRESENCE_VERSION_V1) {
+        if (version != PRESENCE_VERSION_V1) {
             Log.v(TAG, "ExtendedAdvertisement is used in V1 only and version is " + version);
             return null;
         }
 
-        byte[] authenticityKey = publicCredential.getAuthenticityKey();
-
-        int index = HEADER_LENGTH;
-        // Salt
-        byte[] saltHeaderArray = ExtendedAdvertisementUtils.getDataElementHeader(bytes, index);
-        DataElementHeader saltHeader = DataElementHeader.fromBytes(version, saltHeaderArray);
-        if (saltHeader == null || saltHeader.getDataType() != DataElement.DataType.SALT) {
-            Log.v(TAG, "First data element has to be salt.");
+        byte[] keySeed = sharedCredential.getAuthenticityKey();
+        byte[] metadataEncryptionKeyUnsignedAdvTag = sharedCredential.getEncryptedMetadataKeyTag();
+        if (keySeed == null || metadataEncryptionKeyUnsignedAdvTag == null) {
             return null;
         }
-        index += saltHeaderArray.length;
-        byte[] salt = new byte[saltHeader.getDataLength()];
-        for (int i = 0; i < saltHeader.getDataLength(); i++) {
-            salt[i] = bytes[index++];
-        }
 
-        // Identity
+        int index = 0;
+        // Header
+        byte[] header = new byte[]{bytes[index]};
+        index += HEADER_LENGTH;
+        // Section header
+        byte[] sectionHeader = new byte[]{bytes[index]};
+        index += HEADER_LENGTH;
+        // Salt or Encryption Info
+        byte[] firstHeaderArray = ExtendedAdvertisementUtils.getDataElementHeader(bytes, index);
+        DataElementHeader firstHeader = DataElementHeader.fromBytes(version, firstHeaderArray);
+        if (firstHeader == null) {
+            Log.v(TAG, "Cannot find salt.");
+            return null;
+        }
+        @DataType int firstType = firstHeader.getDataType();
+        if (firstType != DataType.SALT && firstType != DataType.ENCRYPTION_INFO) {
+            Log.v(TAG, "First data element has to be Salt or Encryption Info.");
+            return null;
+        }
+        index += firstHeaderArray.length;
+        byte[] firstDeBytes = new byte[firstHeader.getDataLength()];
+        for (int i = 0; i < firstHeader.getDataLength(); i++) {
+            firstDeBytes[i] = bytes[index++];
+        }
+        byte[] nonce = getNonce(firstType, firstDeBytes);
+        if (nonce == null) {
+            return null;
+        }
+        byte[] saltBytes = firstType == DataType.SALT
+                ? firstDeBytes : (new EncryptionInfo(firstDeBytes)).getSalt();
+
+        // Identity header
         byte[] identityHeaderArray = ExtendedAdvertisementUtils.getDataElementHeader(bytes, index);
         DataElementHeader identityHeader =
                 DataElementHeader.fromBytes(version, identityHeaderArray);
-        if (identityHeader == null) {
-            Log.v(TAG, "The second element has to be identity.");
+        if (identityHeader == null || identityHeader.getDataLength() != IDENTITY_DATA_LENGTH) {
+            Log.v(TAG, "The second element has to be a 16-bytes identity.");
             return null;
         }
         index += identityHeaderArray.length;
         @PresenceCredential.IdentityType int identityType =
                 toPresenceCredentialIdentityType(identityHeader.getDataType());
-        if (identityType == PresenceCredential.IDENTITY_TYPE_UNKNOWN) {
-            Log.v(TAG, "The identity type is unknown.");
+        if (identityType != PresenceCredential.IDENTITY_TYPE_PRIVATE
+                && identityType != PresenceCredential.IDENTITY_TYPE_TRUSTED) {
+            Log.v(TAG, "Only supports encrypted advertisement.");
             return null;
         }
-        byte[] encryptedIdentity = new byte[identityHeader.getDataLength()];
-        for (int i = 0; i < identityHeader.getDataLength(); i++) {
-            encryptedIdentity[i] = bytes[index++];
-        }
-        byte[] identity =
-                CryptorImpIdentityV1
-                        .getInstance().decrypt(encryptedIdentity, salt, authenticityKey);
-
-        Cryptor cryptor = getCryptor(/* encrypt= */ true);
-        byte[] encryptedDataElements =
-                new byte[bytes.length - index - cryptor.getSignatureLength()];
-        // Decrypt other data elements
-        System.arraycopy(bytes, index, encryptedDataElements, 0, encryptedDataElements.length);
-        byte[] decryptedDataElements =
-                cryptor.decrypt(encryptedDataElements, salt, authenticityKey);
-        if (decryptedDataElements == null) {
+        // Ciphertext
+        Cryptor cryptor = CryptorMicImp.getInstance();
+        byte[] ciphertext = new byte[bytes.length - index - cryptor.getSignatureLength()];
+        System.arraycopy(bytes, index, ciphertext, 0, ciphertext.length);
+        byte[] plaintext = cryptor.decrypt(ciphertext, nonce, keySeed);
+        if (plaintext == null) {
             return null;
         }
 
+        // Verification
+        // Verify the computed metadata encryption key tag
+        // First 16 bytes is metadata encryption key data
+        byte[] metadataEncryptionKey = new byte[IDENTITY_DATA_LENGTH];
+        System.arraycopy(plaintext, 0, metadataEncryptionKey, 0, IDENTITY_DATA_LENGTH);
+        // Verify metadata encryption key tag
+        byte[] computedMetadataEncryptionKeyTag =
+                CryptorMicImp.generateMetadataEncryptionKeyTag(metadataEncryptionKey,
+                        keySeed);
+        if (!Arrays.equals(computedMetadataEncryptionKeyTag, metadataEncryptionKeyUnsignedAdvTag)) {
+            Log.w(TAG,
+                    "The calculated metadata encryption key tag is different from the metadata "
+                            + "encryption key unsigned adv tag in the SharedCredential.");
+            return null;
+        }
         // Verify the computed HMAC tag is equal to HMAC tag in advertisement
-        if (cryptor.getSignatureLength() > 0) {
-            byte[] expectedHmacTag = new byte[cryptor.getSignatureLength()];
-            System.arraycopy(
-                    bytes, bytes.length - cryptor.getSignatureLength(),
-                    expectedHmacTag, 0, cryptor.getSignatureLength());
-            if (!cryptor.verify(decryptedDataElements, authenticityKey, expectedHmacTag)) {
-                Log.e(TAG, "HMAC tags not match.");
-                return null;
-            }
+        byte[] expectedHmacTag = new byte[cryptor.getSignatureLength()];
+        System.arraycopy(
+                bytes, bytes.length - cryptor.getSignatureLength(),
+                expectedHmacTag, 0, cryptor.getSignatureLength());
+        byte[] micInput =  ArrayUtils.concatByteArrays(
+                PRESENCE_UUID_BYTES, header, sectionHeader,
+                firstHeaderArray, firstDeBytes,
+                nonce, identityHeaderArray, ciphertext);
+        if (!cryptor.verify(micInput, keySeed, expectedHmacTag)) {
+            Log.e(TAG, "HMAC tag not match.");
+            return null;
         }
 
-        int dataElementArrayIndex = 0;
-        // Other Data Elements
-        List<Integer> actions = new ArrayList<>();
-        List<DataElement> dataElements = new ArrayList<>();
-        while (dataElementArrayIndex < decryptedDataElements.length) {
-            byte[] deHeaderArray = ExtendedAdvertisementUtils
-                    .getDataElementHeader(decryptedDataElements, dataElementArrayIndex);
-            DataElementHeader deHeader = DataElementHeader.fromBytes(version, deHeaderArray);
-            dataElementArrayIndex += deHeaderArray.length;
+        byte[] otherDataElements = new byte[plaintext.length - IDENTITY_DATA_LENGTH];
+        System.arraycopy(plaintext, IDENTITY_DATA_LENGTH,
+                otherDataElements, 0, otherDataElements.length);
+        List<DataElement> dataElements = getDataElementsFromBytes(version, otherDataElements);
+        if (dataElements.isEmpty()) {
+            return null;
+        }
+        List<Integer> actions = getActionsFromDataElements(dataElements);
+        if (actions == null) {
+            return null;
+        }
+        return new ExtendedAdvertisement(identityType, metadataEncryptionKey, saltBytes, keySeed,
+                actions, dataElements);
+    }
 
-            @DataElement.DataType int type = Objects.requireNonNull(deHeader).getDataType();
-            if (type == DataElement.DataType.ACTION) {
-                if (deHeader.getDataLength() != 1) {
-                    Log.v(TAG, "Action id should only 1 byte.");
+    @PresenceCredential.IdentityType
+    private static int toPresenceCredentialIdentityType(@DataType int type) {
+        switch (type) {
+            case DataType.PRIVATE_IDENTITY:
+                return PresenceCredential.IDENTITY_TYPE_PRIVATE;
+            case DataType.PROVISIONED_IDENTITY:
+                return PresenceCredential.IDENTITY_TYPE_PROVISIONED;
+            case DataType.TRUSTED_IDENTITY:
+                return PresenceCredential.IDENTITY_TYPE_TRUSTED;
+            case DataType.PUBLIC_IDENTITY:
+            default:
+                return PresenceCredential.IDENTITY_TYPE_UNKNOWN;
+        }
+    }
+
+    @DataType
+    private static int toDataType(@PresenceCredential.IdentityType int identityType) {
+        switch (identityType) {
+            case PresenceCredential.IDENTITY_TYPE_PRIVATE:
+                return DataType.PRIVATE_IDENTITY;
+            case PresenceCredential.IDENTITY_TYPE_PROVISIONED:
+                return DataType.PROVISIONED_IDENTITY;
+            case PresenceCredential.IDENTITY_TYPE_TRUSTED:
+                return DataType.TRUSTED_IDENTITY;
+            case PresenceCredential.IDENTITY_TYPE_UNKNOWN:
+            default:
+                return DataType.PUBLIC_IDENTITY;
+        }
+    }
+
+    /**
+     * Returns {@code true} if the given {@link DataType} is salt, or one of the
+     * identities. Identities should be able to convert to {@link PresenceCredential.IdentityType}s.
+     */
+    private static boolean isSaltOrIdentity(@DataType int type) {
+        return type == DataType.SALT || type == DataType.ENCRYPTION_INFO
+                || type == DataType.PRIVATE_IDENTITY
+                || type == DataType.TRUSTED_IDENTITY
+                || type == DataType.PROVISIONED_IDENTITY
+                || type == DataType.PUBLIC_IDENTITY;
+    }
+
+    /** Serialize an {@link ExtendedAdvertisement} object into bytes with {@link DataElement}s */
+    @Nullable
+    public byte[] toBytes() {
+        return mData.clone();
+    }
+
+    /** Serialize an {@link ExtendedAdvertisement} object into bytes with {@link DataElement}s */
+    @Nullable
+    public byte[] toBytesInternal() {
+        int sectionLength = 0;
+        // Salt
+        DataElement saltDe;
+        byte[] nonce;
+        try {
+            switch (mSalt.length) {
+                case SALT_DATA_LENGTH:
+                    saltDe = new DataElement(DataType.SALT, mSalt);
+                    nonce = CryptorMicImp.generateAdvNonce(mSalt);
+                    break;
+                case ENCRYPTION_INFO_LENGTH - 1:
+                    saltDe = new DataElement(DataType.ENCRYPTION_INFO,
+                            EncryptionInfo.toByte(EncryptionInfo.EncodingScheme.MIC, mSalt));
+                    nonce = CryptorMicImp.generateAdvNonce(mSalt, CIPHER_START_INDEX);
+                    break;
+                default:
+                    Log.w(TAG, "Invalid salt size.");
                     return null;
-                }
-                actions.add((int) decryptedDataElements[dataElementArrayIndex++]);
-            } else {
-                if (isSaltOrIdentity(type)) {
-                    Log.v(TAG, "Type " + type + " is duplicated. There should be only one salt"
-                            + " and one identity in the advertisement.");
-                    return null;
-                }
-                byte[] deData = new byte[deHeader.getDataLength()];
-                for (int i = 0; i < deHeader.getDataLength(); i++) {
-                    deData[i] = decryptedDataElements[dataElementArrayIndex++];
-                }
-                dataElements.add(new DataElement(type, deData));
             }
+        } catch (GeneralSecurityException e) {
+            Log.w(TAG, "Failed to generate the IV for encryption.", e);
+            return null;
         }
 
-        return new ExtendedAdvertisement(identityType, identity, salt, authenticityKey, actions,
-                dataElements);
+        byte[] saltOrEncryptionInfoBytes =
+                ExtendedAdvertisementUtils.convertDataElementToBytes(saltDe);
+        sectionLength += saltOrEncryptionInfoBytes.length;
+        // 16 bytes encrypted identity
+        @DataType int identityDataType = toDataType(getIdentityType());
+        byte[] identityHeaderBytes = new DataElementHeader(PRESENCE_VERSION_V1,
+                identityDataType, mIdentity.length).toBytes();
+        sectionLength += identityHeaderBytes.length;
+        final List<DataElement> dataElementList = getDataElements();
+        byte[] ciphertext = getCiphertext(nonce, dataElementList);
+        if (ciphertext == null) {
+            return null;
+        }
+        sectionLength += ciphertext.length;
+        // mic
+        sectionLength += CryptorMicImp.MIC_LENGTH;
+        mLength = sectionLength;
+        // header
+        byte header = ExtendedAdvertisementUtils.constructHeader(getVersion());
+        mLength += HEADER_LENGTH;
+        // section header
+        if (sectionLength > 255) {
+            Log.e(TAG, "A section should be shorter than 255 bytes.");
+            return null;
+        }
+        byte sectionHeader = (byte) sectionLength;
+        mLength += HEADER_LENGTH;
+
+        // generates mic
+        ByteBuffer micInputBuffer = ByteBuffer.allocate(
+                mLength + PRESENCE_UUID_BYTES.length + nonce.length - CryptorMicImp.MIC_LENGTH);
+        micInputBuffer.put(PRESENCE_UUID_BYTES);
+        micInputBuffer.put(header);
+        micInputBuffer.put(sectionHeader);
+        micInputBuffer.put(saltOrEncryptionInfoBytes);
+        micInputBuffer.put(nonce);
+        micInputBuffer.put(identityHeaderBytes);
+        micInputBuffer.put(ciphertext);
+        byte[] micInput = micInputBuffer.array();
+        byte[] mic = CryptorMicImp.getInstance().sign(micInput, mKeySeed);
+        if (mic == null) {
+            return null;
+        }
+
+        ByteBuffer buffer = ByteBuffer.allocate(mLength);
+        buffer.put(header);
+        buffer.put(sectionHeader);
+        buffer.put(saltOrEncryptionInfoBytes);
+        buffer.put(identityHeaderBytes);
+        buffer.put(ciphertext);
+        buffer.put(mic);
+        return buffer.array();
     }
 
     /** Returns the {@link DataElement}s in the advertisement. */
@@ -260,7 +382,7 @@
     }
 
     /** Returns the {@link DataElement}s in the advertisement according to the key. */
-    public List<DataElement> getDataElements(@DataElement.DataType int key) {
+    public List<DataElement> getDataElements(@DataType int key) {
         List<DataElement> res = new ArrayList<>();
         for (DataElement dataElement : mDataElements) {
             if (key == dataElement.getKey()) {
@@ -285,125 +407,86 @@
                 getActions());
     }
 
-    ExtendedAdvertisement(
-            @PresenceCredential.IdentityType int identityType,
-            byte[] identity,
-            byte[] salt,
-            byte[] authenticityKey,
-            List<Integer> actions,
-            List<DataElement> dataElements) {
-        this.mVersion = BroadcastRequest.PRESENCE_VERSION_V1;
-        this.mIdentityType = identityType;
-        this.mIdentity = identity;
-        this.mSalt = salt;
-        this.mAuthenticityKey = authenticityKey;
-        this.mActions = actions;
-        this.mDataElements = dataElements;
-        this.mCompleteDataElementsBytes = new ArrayList<>();
+    @Nullable
+    private byte[] getCiphertext(byte[] nonce, List<DataElement> dataElements) {
+        Cryptor cryptor = CryptorMicImp.getInstance();
+        byte[] rawDeBytes = mIdentity;
+        for (DataElement dataElement : dataElements) {
+            rawDeBytes = ArrayUtils.concatByteArrays(rawDeBytes,
+                    ExtendedAdvertisementUtils.convertDataElementToBytes(dataElement));
+        }
+        return cryptor.encrypt(rawDeBytes, nonce, mKeySeed);
+    }
 
-        int length = HEADER_LENGTH; // header
+    private static List<DataElement> getDataElementsFromBytes(
+            @BroadcastVersion int version, byte[] bytes) {
+        List<DataElement> res = new ArrayList<>();
+        if (ArrayUtils.isEmpty(bytes)) {
+            return res;
+        }
+        int index = 0;
+        while (index < bytes.length) {
+            byte[] deHeaderArray = ExtendedAdvertisementUtils
+                    .getDataElementHeader(bytes, index);
+            DataElementHeader deHeader = DataElementHeader.fromBytes(version, deHeaderArray);
+            index += deHeaderArray.length;
+            @DataType int type = Objects.requireNonNull(deHeader).getDataType();
+            if (isSaltOrIdentity(type)) {
+                Log.v(TAG, "Type " + type + " is duplicated. There should be only one salt"
+                        + " and one identity in the advertisement.");
+                return new ArrayList<>();
+            }
+            byte[] deData = new byte[deHeader.getDataLength()];
+            for (int i = 0; i < deHeader.getDataLength(); i++) {
+                deData[i] = bytes[index++];
+            }
+            res.add(new DataElement(type, deData));
+        }
+        return res;
+    }
 
-        // Salt
-        DataElement saltElement = new DataElement(DataElement.DataType.SALT, salt);
-        byte[] saltByteArray = ExtendedAdvertisementUtils.convertDataElementToBytes(saltElement);
-        mCompleteDataElementsBytes.add(saltByteArray);
-        length += saltByteArray.length;
+    @Nullable
+    private static byte[] getNonce(@DataType int type, byte[] data) {
+        try {
+            if (type == DataType.SALT) {
+                if (data.length != SALT_DATA_LENGTH) {
+                    Log.v(TAG, "Salt DataElement needs to be 2 bytes.");
+                    return null;
+                }
+                return CryptorMicImp.generateAdvNonce(data);
+            } else if (type == DataType.ENCRYPTION_INFO) {
+                try {
+                    EncryptionInfo info = new EncryptionInfo(data);
+                    if (info.getEncodingScheme() != EncryptionInfo.EncodingScheme.MIC) {
+                        Log.v(TAG, "Not support Signature yet.");
+                        return null;
+                    }
+                    return CryptorMicImp.generateAdvNonce(info.getSalt(), CIPHER_START_INDEX);
+                } catch (IllegalArgumentException e) {
+                    Log.w(TAG, "Salt DataElement needs to be 17 bytes.", e);
+                    return null;
+                }
+            }
+        }  catch (GeneralSecurityException e) {
+            Log.w(TAG, "Failed to decrypt metadata encryption key.", e);
+            return null;
+        }
+        return null;
+    }
 
-        // Identity
-        byte[] encryptedIdentity =
-                CryptorImpIdentityV1.getInstance().encrypt(identity, salt, authenticityKey);
-        DataElement identityElement = new DataElement(toDataType(identityType), encryptedIdentity);
-        byte[] identityByteArray =
-                ExtendedAdvertisementUtils.convertDataElementToBytes(identityElement);
-        mCompleteDataElementsBytes.add(identityByteArray);
-        length += identityByteArray.length;
-
-        List<Byte> dataElementBytes = new ArrayList<>();
-        // Intents
-        for (int action : mActions) {
-            DataElement actionElement = new DataElement(DataElement.DataType.ACTION,
-                    new byte[] {(byte) action});
-            byte[] intentByteArray =
-                    ExtendedAdvertisementUtils.convertDataElementToBytes(actionElement);
-            mCompleteDataElementsBytes.add(intentByteArray);
-            for (Byte b : intentByteArray) {
-                dataElementBytes.add(b);
+    @Nullable
+    private static List<Integer> getActionsFromDataElements(List<DataElement> dataElements) {
+        List<Integer> actions = new ArrayList<>();
+        for (DataElement dataElement : dataElements) {
+            if (dataElement.getKey() == DataElement.DataType.ACTION) {
+                byte[] value = dataElement.getValue();
+                if (value.length != 1) {
+                    Log.w(TAG, "Action should be only 1 byte.");
+                    return null;
+                }
+                actions.add(Byte.toUnsignedInt(value[0]));
             }
         }
-
-        // Data Elements (Extended properties)
-        for (DataElement dataElement : mDataElements) {
-            byte[] deByteArray = ExtendedAdvertisementUtils.convertDataElementToBytes(dataElement);
-            mCompleteDataElementsBytes.add(deByteArray);
-            for (Byte b : deByteArray) {
-                dataElementBytes.add(b);
-            }
-        }
-
-        byte[] data = new byte[dataElementBytes.size()];
-        for (int i = 0; i < dataElementBytes.size(); i++) {
-            data[i] = dataElementBytes.get(i);
-        }
-        Cryptor cryptor = getCryptor(/* encrypt= */ true);
-        byte[] encryptedDeBytes = cryptor.encrypt(data, salt, authenticityKey);
-
-        length += encryptedDeBytes.length;
-
-        // Signature
-        byte[] hmacTag = Objects.requireNonNull(cryptor.sign(data, authenticityKey));
-        mHmacTag = hmacTag;
-        length += hmacTag.length;
-
-        this.mLength = length;
-    }
-
-    @PresenceCredential.IdentityType
-    private static int toPresenceCredentialIdentityType(@DataElement.DataType int type) {
-        switch (type) {
-            case DataElement.DataType.PRIVATE_IDENTITY:
-                return PresenceCredential.IDENTITY_TYPE_PRIVATE;
-            case DataElement.DataType.PROVISIONED_IDENTITY:
-                return PresenceCredential.IDENTITY_TYPE_PROVISIONED;
-            case DataElement.DataType.TRUSTED_IDENTITY:
-                return PresenceCredential.IDENTITY_TYPE_TRUSTED;
-            case DataElement.DataType.PUBLIC_IDENTITY:
-            default:
-                return PresenceCredential.IDENTITY_TYPE_UNKNOWN;
-        }
-    }
-
-    @DataElement.DataType
-    private static int toDataType(@PresenceCredential.IdentityType int identityType) {
-        switch (identityType) {
-            case PresenceCredential.IDENTITY_TYPE_PRIVATE:
-                return DataElement.DataType.PRIVATE_IDENTITY;
-            case PresenceCredential.IDENTITY_TYPE_PROVISIONED:
-                return DataElement.DataType.PROVISIONED_IDENTITY;
-            case PresenceCredential.IDENTITY_TYPE_TRUSTED:
-                return DataElement.DataType.TRUSTED_IDENTITY;
-            case PresenceCredential.IDENTITY_TYPE_UNKNOWN:
-            default:
-                return DataElement.DataType.PUBLIC_IDENTITY;
-        }
-    }
-
-    /**
-     * Returns {@code true} if the given {@link DataElement.DataType} is salt, or one of the
-     * identities. Identities should be able to convert to {@link PresenceCredential.IdentityType}s.
-     */
-    private static boolean isSaltOrIdentity(@DataElement.DataType int type) {
-        return type == DataElement.DataType.SALT || type == DataElement.DataType.PRIVATE_IDENTITY
-                || type == DataElement.DataType.TRUSTED_IDENTITY
-                || type == DataElement.DataType.PROVISIONED_IDENTITY
-                || type == DataElement.DataType.PUBLIC_IDENTITY;
-    }
-
-    private static Cryptor getCryptor(boolean encrypt) {
-        if (encrypt) {
-            Log.d(TAG, "get V1 Cryptor");
-            return CryptorImpV1.getInstance();
-        }
-        Log.d(TAG, "get fake Cryptor");
-        return CryptorImpFake.getInstance();
+        return actions;
     }
 }
diff --git a/nearby/service/java/com/android/server/nearby/presence/PresenceConstants.java b/nearby/service/java/com/android/server/nearby/presence/PresenceConstants.java
index 54264f7..50dada2 100644
--- a/nearby/service/java/com/android/server/nearby/presence/PresenceConstants.java
+++ b/nearby/service/java/com/android/server/nearby/presence/PresenceConstants.java
@@ -18,10 +18,15 @@
 
 import android.os.ParcelUuid;
 
+import com.android.server.nearby.util.ArrayUtils;
+
 /**
  * Constants for Nearby Presence operations.
  */
 public class PresenceConstants {
+    /** The Presence UUID value in byte array format. */
+    public static final byte[] PRESENCE_UUID_BYTES = ArrayUtils.intToByteArray(0xFCF1);
+
     /** Presence advertisement service data uuid. */
     public static final ParcelUuid PRESENCE_UUID =
             ParcelUuid.fromString("0000fcf1-0000-1000-8000-00805f9b34fb");
diff --git a/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java b/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
index 355f7cf..9dd07a4 100644
--- a/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
+++ b/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
@@ -45,7 +45,6 @@
 import com.android.server.nearby.presence.ExtendedAdvertisement;
 import com.android.server.nearby.util.ArrayUtils;
 import com.android.server.nearby.util.ForegroundThread;
-import com.android.server.nearby.util.encryption.CryptorImpIdentityV1;
 
 import com.google.common.annotations.VisibleForTesting;
 
@@ -133,10 +132,6 @@
                         .addMedium(NearbyDevice.Medium.BLE)
                         .setName(deviceName)
                         .setRssi(rssi);
-        for (int i : advertisement.getActions()) {
-            builder.addExtendedProperty(new DataElement(DataElement.DataType.ACTION,
-                    new byte[]{(byte) i}));
-        }
         for (DataElement dataElement : advertisement.getDataElements()) {
             builder.addExtendedProperty(dataElement);
         }
@@ -284,17 +279,13 @@
                         if (advertisement == null) {
                             continue;
                         }
-                        if (CryptorImpIdentityV1.getInstance().verify(
-                                advertisement.getIdentity(),
-                                credential.getEncryptedMetadataKeyTag())) {
-                            builder.setPresenceDevice(getPresenceDevice(advertisement, deviceName,
-                                    rssi));
-                            builder.setEncryptionKeyTag(credential.getEncryptedMetadataKeyTag());
-                            if (!ArrayUtils.isEmpty(credential.getSecretId())) {
-                                builder.setDeviceId(Arrays.hashCode(credential.getSecretId()));
-                            }
-                            return;
+                        builder.setPresenceDevice(getPresenceDevice(advertisement, deviceName,
+                                rssi));
+                        builder.setEncryptionKeyTag(credential.getEncryptedMetadataKeyTag());
+                        if (!ArrayUtils.isEmpty(credential.getSecretId())) {
+                            builder.setDeviceId(Arrays.hashCode(credential.getSecretId()));
                         }
+                        return;
                     }
                 }
             }
diff --git a/nearby/service/java/com/android/server/nearby/util/ArrayUtils.java b/nearby/service/java/com/android/server/nearby/util/ArrayUtils.java
index bb5461c..e69d004 100644
--- a/nearby/service/java/com/android/server/nearby/util/ArrayUtils.java
+++ b/nearby/service/java/com/android/server/nearby/util/ArrayUtils.java
@@ -22,6 +22,10 @@
  * ArrayUtils class that help manipulate array.
  */
 public class ArrayUtils {
+    private static final char[] HEX_UPPERCASE = {
+            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
+    };
+
     /** Concatenate N arrays of bytes into a single array. */
     public static byte[] concatByteArrays(byte[]... arrays) {
         // Degenerate case - no input provided.
@@ -65,4 +69,54 @@
         System.arraycopy(b, 0, result, 1, length);
         return result;
     }
+
+    /**
+     * Converts an Integer to a 2-byte array.
+     */
+    public static byte[] intToByteArray(int value) {
+        return new byte[] {(byte) (value >> 8), (byte) value};
+    }
+
+    /** Appends a byte to a byte array. */
+    public static byte[] append(byte[] a, byte b) {
+        if (a == null) {
+            return new byte[]{b};
+        }
+
+        int length = a.length;
+        byte[] result = new byte[length + 1];
+        System.arraycopy(a, 0, result, 0, length);
+        result[length] = b;
+        return result;
+    }
+
+    /** Convert an hex string to a byte array. */
+
+    public static byte[] stringToBytes(String hex) throws IllegalArgumentException {
+        int length = hex.length();
+        if (length % 2 != 0) {
+            throw new IllegalArgumentException("Hex string has odd number of characters");
+        }
+        byte[] out = new byte[length / 2];
+        for (int i = 0; i < length; i += 2) {
+            // Byte.parseByte() doesn't work here because it expects a hex value in -128, 127, and
+            // our hex values are in 0, 255.
+            out[i / 2] = (byte) Integer.parseInt(hex.substring(i, i + 2), 16);
+        }
+        return out;
+    }
+
+    /** Encodes a byte array as a hexadecimal representation of bytes. */
+    public static String bytesToStringUppercase(byte[] bytes) {
+        int length = bytes.length;
+        StringBuilder out = new StringBuilder(length * 2);
+        for (int i = 0; i < length; i++) {
+            if (i == length - 1 && (bytes[i] & 0xff) == 0) {
+                break;
+            }
+            out.append(HEX_UPPERCASE[(bytes[i] & 0xf0) >>> 4]);
+            out.append(HEX_UPPERCASE[bytes[i] & 0x0f]);
+        }
+        return out.toString();
+    }
 }
diff --git a/nearby/service/java/com/android/server/nearby/util/encryption/Cryptor.java b/nearby/service/java/com/android/server/nearby/util/encryption/Cryptor.java
index 3c5132d..ba9ca41 100644
--- a/nearby/service/java/com/android/server/nearby/util/encryption/Cryptor.java
+++ b/nearby/service/java/com/android/server/nearby/util/encryption/Cryptor.java
@@ -22,6 +22,10 @@
 
 import androidx.annotation.Nullable;
 
+import com.google.common.hash.Hashing;
+
+import java.nio.charset.StandardCharsets;
+import java.security.GeneralSecurityException;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 
@@ -30,22 +34,28 @@
 
 /** Class for encryption/decryption functionality. */
 public abstract class Cryptor {
+    /**
+     * In the form of "algorithm/mode/padding". Must be the same across broadcast and scan devices.
+     */
+    public static final String CIPHER_ALGORITHM = "AES/CTR/NoPadding";
+
+    public static final byte[] NP_HKDF_SALT = "Google Nearby".getBytes(StandardCharsets.US_ASCII);
 
     /** AES only supports key sizes of 16, 24 or 32 bytes. */
     static final int AUTHENTICITY_KEY_BYTE_SIZE = 16;
 
-    private static final String HMAC_SHA256_ALGORITHM = "HmacSHA256";
+    public static final String HMAC_SHA256_ALGORITHM = "HmacSHA256";
 
     /**
      * Encrypt the provided data blob.
      *
      * @param data data blob to be encrypted.
-     * @param salt used for IV
+     * @param iv advertisement nonce
      * @param secretKeyBytes secrete key accessed from credentials
      * @return encrypted data, {@code null} if failed to encrypt.
      */
     @Nullable
-    public byte[] encrypt(byte[] data, byte[] salt, byte[] secretKeyBytes) {
+    public byte[] encrypt(byte[] data, byte[] iv, byte[] secretKeyBytes) {
         return data;
     }
 
@@ -53,12 +63,12 @@
      * Decrypt the original data blob from the provided byte array.
      *
      * @param encryptedData data blob to be decrypted.
-     * @param salt used for IV
+     * @param iv advertisement nonce
      * @param secretKeyBytes secrete key accessed from credentials
      * @return decrypted data, {@code null} if failed to decrypt.
      */
     @Nullable
-    public byte[] decrypt(byte[] encryptedData, byte[] salt, byte[] secretKeyBytes) {
+    public byte[] decrypt(byte[] encryptedData, byte[] iv, byte[] secretKeyBytes) {
         return encryptedData;
     }
 
@@ -90,7 +100,7 @@
      * A HAMC sha256 based HKDF algorithm to pseudo randomly hash data and salt into a byte array of
      * given size.
      */
-    // Based on google3/third_party/tink/java/src/main/java/com/google/crypto/tink/subtle/Hkdf.java
+    // Based on crypto/tink/subtle/Hkdf.java
     @Nullable
     static byte[] computeHkdf(byte[] ikm, byte[] salt, int size) {
         Mac mac;
@@ -146,4 +156,66 @@
 
         return result;
     }
+
+    /**
+     * Computes an HKDF.
+     *
+     * @param macAlgorithm the MAC algorithm used for computing the Hkdf. I.e., "HMACSHA1" or
+     *                     "HMACSHA256".
+     * @param ikm          the input keying material.
+     * @param salt         optional salt. A possibly non-secret random value.
+     *                     (If no salt is provided i.e. if salt has length 0)
+     *                     then an array of 0s of the same size as the hash
+     *                     digest is used as salt.
+     * @param info         optional context and application specific information.
+     * @param size         The length of the generated pseudorandom string in bytes.
+     * @throws GeneralSecurityException if the {@code macAlgorithm} is not supported or if {@code
+     *                                  size} is too large or if {@code salt} is not a valid key for
+     *                                  macAlgorithm (which should not
+     *                                  happen since HMAC allows key sizes up to 2^64).
+     */
+    public static byte[] computeHkdf(
+            String macAlgorithm, final byte[] ikm, final byte[] salt, final byte[] info, int size)
+            throws GeneralSecurityException {
+        Mac mac = Mac.getInstance(macAlgorithm);
+        if (size > 255 * mac.getMacLength()) {
+            throw new GeneralSecurityException("size too large");
+        }
+        if (salt == null || salt.length == 0) {
+            // According to RFC 5869, Section 2.2 the salt is optional. If no salt is provided
+            // then HKDF uses a salt that is an array of zeros of the same length as the hash
+            // digest.
+            mac.init(new SecretKeySpec(new byte[mac.getMacLength()], macAlgorithm));
+        } else {
+            mac.init(new SecretKeySpec(salt, macAlgorithm));
+        }
+        byte[] prk = mac.doFinal(ikm);
+        byte[] result = new byte[size];
+        int ctr = 1;
+        int pos = 0;
+        mac.init(new SecretKeySpec(prk, macAlgorithm));
+        byte[] digest = new byte[0];
+        while (true) {
+            mac.update(digest);
+            mac.update(info);
+            mac.update((byte) ctr);
+            digest = mac.doFinal();
+            if (pos + digest.length < size) {
+                System.arraycopy(digest, 0, result, pos, digest.length);
+                pos += digest.length;
+                ctr++;
+            } else {
+                System.arraycopy(digest, 0, result, pos, size - pos);
+                break;
+            }
+        }
+        return result;
+    }
+
+    /** Generates the HMAC bytes. */
+    public static byte[] generateHmac(String algorithm, byte[] input, byte[] key) {
+        return Hashing.hmacSha256(new SecretKeySpec(key, algorithm))
+                .hashBytes(input)
+                .asBytes();
+    }
 }
diff --git a/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpFake.java b/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpFake.java
deleted file mode 100644
index 1c0ec9e..0000000
--- a/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpFake.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright (C) 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.android.server.nearby.util.encryption;
-
-import androidx.annotation.Nullable;
-
-/**
- * A Cryptor that returns the original data without actual encryption
- */
-public class CryptorImpFake extends Cryptor {
-    // Lazily instantiated when {@link #getInstance()} is called.
-    @Nullable
-    private static CryptorImpFake sCryptor;
-
-    /** Returns an instance of CryptorImpFake. */
-    public static CryptorImpFake getInstance() {
-        if (sCryptor == null) {
-            sCryptor = new CryptorImpFake();
-        }
-        return sCryptor;
-    }
-
-    private CryptorImpFake() {
-    }
-}
diff --git a/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpIdentityV1.java b/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpIdentityV1.java
deleted file mode 100644
index b0e19b4..0000000
--- a/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpIdentityV1.java
+++ /dev/null
@@ -1,208 +0,0 @@
-/*
- * Copyright (C) 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.android.server.nearby.util.encryption;
-
-import static com.android.server.nearby.NearbyService.TAG;
-
-import android.security.keystore.KeyProperties;
-import android.util.Log;
-
-import androidx.annotation.Nullable;
-
-import com.android.internal.annotations.VisibleForTesting;
-
-import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.NoSuchAlgorithmException;
-import java.util.Arrays;
-
-import javax.crypto.BadPaddingException;
-import javax.crypto.Cipher;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.NoSuchPaddingException;
-import javax.crypto.SecretKey;
-import javax.crypto.spec.IvParameterSpec;
-import javax.crypto.spec.SecretKeySpec;
-
-/**
- * {@link android.nearby.BroadcastRequest#PRESENCE_VERSION_V1} for identity
- * encryption and decryption.
- */
-public class CryptorImpIdentityV1 extends Cryptor {
-
-    // 3 16 byte arrays known by both the encryptor and decryptor.
-    private static final byte[] EK_IV =
-            new byte[] {14, -123, -39, 42, 109, 127, 83, 27, 27, 11, 91, -38, 92, 17, -84, 66};
-    private static final byte[] ESALT_IV =
-            new byte[] {46, 83, -19, 10, -127, -31, -31, 12, 31, 76, 63, -9, 33, -66, 15, -10};
-    private static final byte[] KTAG_IV =
-            {-22, -83, -6, 67, 16, -99, -13, -9, 8, -3, -16, 37, -75, 47, 1, -56};
-
-    /** Length of encryption key required by AES/GCM encryption. */
-    private static final int ENCRYPTION_KEY_SIZE = 32;
-
-    /** Length of salt required by AES/GCM encryption. */
-    private static final int AES_CTR_IV_SIZE = 16;
-
-    /** Length HMAC tag */
-    public static final int HMAC_TAG_SIZE = 8;
-
-    /**
-     * In the form of "algorithm/mode/padding". Must be the same across broadcast and scan devices.
-     */
-    private static final String CIPHER_ALGORITHM = "AES/CTR/NoPadding";
-
-    @VisibleForTesting
-    static final String ENCRYPT_ALGORITHM = KeyProperties.KEY_ALGORITHM_AES;
-
-    // Lazily instantiated when {@link #getInstance()} is called.
-    @Nullable private static CryptorImpIdentityV1 sCryptor;
-
-    /** Returns an instance of CryptorImpIdentityV1. */
-    public static CryptorImpIdentityV1 getInstance() {
-        if (sCryptor == null) {
-            sCryptor = new CryptorImpIdentityV1();
-        }
-        return sCryptor;
-    }
-
-    @Nullable
-    @Override
-    public byte[] encrypt(byte[] data, byte[] salt, byte[] authenticityKey) {
-        if (authenticityKey.length != AUTHENTICITY_KEY_BYTE_SIZE) {
-            Log.w(TAG, "Illegal authenticity key size");
-            return null;
-        }
-
-        // Generates a 32 bytes encryption key from authenticity_key
-        byte[] encryptionKey = Cryptor.computeHkdf(authenticityKey, EK_IV, ENCRYPTION_KEY_SIZE);
-        if (encryptionKey == null) {
-            Log.e(TAG, "Failed to generate encryption key.");
-            return null;
-        }
-
-        // Encrypts the data using the encryption key
-        SecretKey secretKey = new SecretKeySpec(encryptionKey, ENCRYPT_ALGORITHM);
-        Cipher cipher;
-        try {
-            cipher = Cipher.getInstance(CIPHER_ALGORITHM);
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
-            Log.e(TAG, "Failed to encrypt with secret key.", e);
-            return null;
-        }
-        byte[] esalt = Cryptor.computeHkdf(salt, ESALT_IV, AES_CTR_IV_SIZE);
-        if (esalt == null) {
-            Log.e(TAG, "Failed to generate salt.");
-            return null;
-        }
-        try {
-            cipher.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(esalt));
-        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
-            Log.e(TAG, "Failed to initialize cipher.", e);
-            return null;
-        }
-        try {
-            return cipher.doFinal(data);
-        } catch (IllegalBlockSizeException | BadPaddingException e) {
-            Log.e(TAG, "Failed to encrypt with secret key.", e);
-            return null;
-        }
-    }
-
-    @Nullable
-    @Override
-    public byte[] decrypt(byte[] encryptedData, byte[] salt, byte[] authenticityKey) {
-        if (authenticityKey.length != AUTHENTICITY_KEY_BYTE_SIZE) {
-            Log.w(TAG, "Illegal authenticity key size");
-            return null;
-        }
-
-        // Generates a 32 bytes encryption key from authenticity_key
-        byte[] encryptionKey = Cryptor.computeHkdf(authenticityKey, EK_IV, ENCRYPTION_KEY_SIZE);
-        if (encryptionKey == null) {
-            Log.e(TAG, "Failed to generate encryption key.");
-            return null;
-        }
-
-        // Decrypts the data using the encryption key
-        SecretKey secretKey = new SecretKeySpec(encryptionKey, ENCRYPT_ALGORITHM);
-        Cipher cipher;
-        try {
-            cipher = Cipher.getInstance(CIPHER_ALGORITHM);
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
-            Log.e(TAG, "Failed to get cipher instance.", e);
-            return null;
-        }
-        byte[] esalt = Cryptor.computeHkdf(salt, ESALT_IV, AES_CTR_IV_SIZE);
-        if (esalt == null) {
-            return null;
-        }
-        try {
-            cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(esalt));
-        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
-            Log.e(TAG, "Failed to initialize cipher.", e);
-            return null;
-        }
-
-        try {
-            return cipher.doFinal(encryptedData);
-        } catch (IllegalBlockSizeException | BadPaddingException e) {
-            Log.e(TAG, "Failed to decrypt bytes with secret key.", e);
-            return null;
-        }
-    }
-
-    /**
-     * Generates a digital signature for the data.
-     *
-     * @return signature {@code null} if failed to sign
-     */
-    @Nullable
-    @Override
-    public byte[] sign(byte[] data, byte[] salt) {
-        if (data == null) {
-            Log.e(TAG, "Not generate HMAC tag because of invalid data input.");
-            return null;
-        }
-
-        // Generates a 8 bytes HMAC tag
-        return Cryptor.computeHkdf(data, salt, HMAC_TAG_SIZE);
-    }
-
-    /**
-     * Generates a digital signature for the data.
-     * Uses KTAG_IV as salt value.
-     */
-    @Nullable
-    public byte[] sign(byte[] data) {
-        // Generates a 8 bytes HMAC tag
-        return sign(data, KTAG_IV);
-    }
-
-    @Override
-    public boolean verify(byte[] data, byte[] key, byte[] signature) {
-        return Arrays.equals(sign(data, key), signature);
-    }
-
-    /**
-     * Verifies the signature generated by data and key, with the original signed data. Uses
-     * KTAG_IV as salt value.
-     */
-    public boolean verify(byte[] data, byte[] signature) {
-        return verify(data, KTAG_IV, signature);
-    }
-}
diff --git a/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpV1.java b/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpV1.java
deleted file mode 100644
index 15073fb..0000000
--- a/nearby/service/java/com/android/server/nearby/util/encryption/CryptorImpV1.java
+++ /dev/null
@@ -1,212 +0,0 @@
-/*
- * Copyright (C) 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.android.server.nearby.util.encryption;
-
-import static com.android.server.nearby.NearbyService.TAG;
-
-import android.security.keystore.KeyProperties;
-import android.util.Log;
-
-import androidx.annotation.Nullable;
-
-import com.android.internal.annotations.VisibleForTesting;
-
-import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.NoSuchAlgorithmException;
-import java.util.Arrays;
-
-import javax.crypto.BadPaddingException;
-import javax.crypto.Cipher;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.NoSuchPaddingException;
-import javax.crypto.SecretKey;
-import javax.crypto.spec.IvParameterSpec;
-import javax.crypto.spec.SecretKeySpec;
-
-/**
- * {@link android.nearby.BroadcastRequest#PRESENCE_VERSION_V1} for encryption and decryption.
- */
-public class CryptorImpV1 extends Cryptor {
-
-    /**
-     * In the form of "algorithm/mode/padding". Must be the same across broadcast and scan devices.
-     */
-    private static final String CIPHER_ALGORITHM = "AES/CTR/NoPadding";
-
-    @VisibleForTesting
-    static final String ENCRYPT_ALGORITHM = KeyProperties.KEY_ALGORITHM_AES;
-
-    /** Length of encryption key required by AES/GCM encryption. */
-    private static final int ENCRYPTION_KEY_SIZE = 32;
-
-    /** Length of salt required by AES/GCM encryption. */
-    private static final int AES_CTR_IV_SIZE = 16;
-
-    /** Length HMAC tag */
-    public static final int HMAC_TAG_SIZE = 16;
-
-    // 3 16 byte arrays known by both the encryptor and decryptor.
-    private static final byte[] AK_IV =
-            new byte[] {12, -59, 19, 23, 96, 57, -59, 19, 117, -31, -116, -61, 86, -25, -33, -78};
-    private static final byte[] ASALT_IV =
-            new byte[] {111, 48, -83, -79, -10, -102, -16, 73, 43, 55, 102, -127, 58, -19, -113, 4};
-    private static final byte[] HK_IV =
-            new byte[] {12, -59, 19, 23, 96, 57, -59, 19, 117, -31, -116, -61, 86, -25, -33, -78};
-
-    // Lazily instantiated when {@link #getInstance()} is called.
-    @Nullable private static CryptorImpV1 sCryptor;
-
-    /** Returns an instance of CryptorImpV1. */
-    public static CryptorImpV1 getInstance() {
-        if (sCryptor == null) {
-            sCryptor = new CryptorImpV1();
-        }
-        return sCryptor;
-    }
-
-    private CryptorImpV1() {
-    }
-
-    @Nullable
-    @Override
-    public byte[] encrypt(byte[] data, byte[] salt, byte[] authenticityKey) {
-        if (authenticityKey.length != AUTHENTICITY_KEY_BYTE_SIZE) {
-            Log.w(TAG, "Illegal authenticity key size");
-            return null;
-        }
-
-        // Generates a 32 bytes encryption key from authenticity_key
-        byte[] encryptionKey = Cryptor.computeHkdf(authenticityKey, AK_IV, ENCRYPTION_KEY_SIZE);
-        if (encryptionKey == null) {
-            Log.e(TAG, "Failed to generate encryption key.");
-            return null;
-        }
-
-        // Encrypts the data using the encryption key
-        SecretKey secretKey = new SecretKeySpec(encryptionKey, ENCRYPT_ALGORITHM);
-        Cipher cipher;
-        try {
-            cipher = Cipher.getInstance(CIPHER_ALGORITHM);
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
-            Log.e(TAG, "Failed to encrypt with secret key.", e);
-            return null;
-        }
-        byte[] asalt = Cryptor.computeHkdf(salt, ASALT_IV, AES_CTR_IV_SIZE);
-        if (asalt == null) {
-            Log.e(TAG, "Failed to generate salt.");
-            return null;
-        }
-        try {
-            cipher.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(asalt));
-        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
-            Log.e(TAG, "Failed to initialize cipher.", e);
-            return null;
-        }
-        try {
-            return cipher.doFinal(data);
-        } catch (IllegalBlockSizeException | BadPaddingException e) {
-            Log.e(TAG, "Failed to encrypt with secret key.", e);
-            return null;
-        }
-    }
-
-    @Nullable
-    @Override
-    public byte[] decrypt(byte[] encryptedData, byte[] salt, byte[] authenticityKey) {
-        if (authenticityKey.length != AUTHENTICITY_KEY_BYTE_SIZE) {
-            Log.w(TAG, "Illegal authenticity key size");
-            return null;
-        }
-
-        // Generates a 32 bytes encryption key from authenticity_key
-        byte[] encryptionKey = Cryptor.computeHkdf(authenticityKey, AK_IV, ENCRYPTION_KEY_SIZE);
-        if (encryptionKey == null) {
-            Log.e(TAG, "Failed to generate encryption key.");
-            return null;
-        }
-
-        // Decrypts the data using the encryption key
-        SecretKey secretKey = new SecretKeySpec(encryptionKey, ENCRYPT_ALGORITHM);
-        Cipher cipher;
-        try {
-            cipher = Cipher.getInstance(CIPHER_ALGORITHM);
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
-            Log.e(TAG, "Failed to get cipher instance.", e);
-            return null;
-        }
-        byte[] asalt = Cryptor.computeHkdf(salt, ASALT_IV, AES_CTR_IV_SIZE);
-        if (asalt == null) {
-            return null;
-        }
-        try {
-            cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(asalt));
-        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
-            Log.e(TAG, "Failed to initialize cipher.", e);
-            return null;
-        }
-
-        try {
-            return cipher.doFinal(encryptedData);
-        } catch (IllegalBlockSizeException | BadPaddingException e) {
-            Log.e(TAG, "Failed to decrypt bytes with secret key.", e);
-            return null;
-        }
-    }
-
-    @Override
-    @Nullable
-    public byte[] sign(byte[] data, byte[] key) {
-        return generateHmacTag(data, key);
-    }
-
-    @Override
-    public int getSignatureLength() {
-        return HMAC_TAG_SIZE;
-    }
-
-    @Override
-    public boolean verify(byte[] data, byte[] key, byte[] signature) {
-        return Arrays.equals(sign(data, key), signature);
-    }
-
-    /** Generates a 16 bytes HMAC tag. This is used for decryptor to verify if the computed HMAC tag
-     * is equal to HMAC tag in advertisement to see data integrity. */
-    @Nullable
-    @VisibleForTesting
-    byte[] generateHmacTag(byte[] data, byte[] authenticityKey) {
-        if (data == null || authenticityKey == null) {
-            Log.e(TAG, "Not generate HMAC tag because of invalid data input.");
-            return null;
-        }
-
-        if (authenticityKey.length != AUTHENTICITY_KEY_BYTE_SIZE) {
-            Log.e(TAG, "Illegal authenticity key size");
-            return null;
-        }
-
-        // Generates a 32 bytes HMAC key from authenticity_key
-        byte[] hmacKey = Cryptor.computeHkdf(authenticityKey, HK_IV, AES_CTR_IV_SIZE);
-        if (hmacKey == null) {
-            Log.e(TAG, "Failed to generate HMAC key.");
-            return null;
-        }
-
-        // Generates a 16 bytes HMAC tag from authenticity_key
-        return Cryptor.computeHkdf(data, hmacKey, HMAC_TAG_SIZE);
-    }
-}
diff --git a/nearby/service/java/com/android/server/nearby/util/encryption/CryptorMicImp.java b/nearby/service/java/com/android/server/nearby/util/encryption/CryptorMicImp.java
new file mode 100644
index 0000000..3dbf85c
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/util/encryption/CryptorMicImp.java
@@ -0,0 +1,286 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.util.encryption;
+
+import static com.android.server.nearby.NearbyService.TAG;
+
+import android.security.keystore.KeyProperties;
+import android.util.Log;
+
+import androidx.annotation.Nullable;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.nearby.util.ArrayUtils;
+
+import java.nio.charset.StandardCharsets;
+import java.security.GeneralSecurityException;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+/**
+ * MIC encryption and decryption for {@link android.nearby.BroadcastRequest#PRESENCE_VERSION_V1}
+ * advertisement
+ */
+public class CryptorMicImp extends Cryptor {
+
+    public static final int MIC_LENGTH = 16;
+
+    private static final String ENCRYPT_ALGORITHM = KeyProperties.KEY_ALGORITHM_AES;
+    private static final byte[] AES_KEY_INFO_BYTES = "Unsigned Section AES key".getBytes(
+            StandardCharsets.US_ASCII);
+    private static final byte[] ADV_NONCE_INFO_BYTES_SALT_DE = "Unsigned Section IV".getBytes(
+            StandardCharsets.US_ASCII);
+    private static final byte[] ADV_NONCE_INFO_BYTES_ENCRYPTION_INFO_DE =
+            "V1 derived salt".getBytes(StandardCharsets.US_ASCII);
+    private static final byte[] METADATA_KEY_HMAC_KEY_INFO_BYTES =
+            "Unsigned Section metadata key HMAC key".getBytes(StandardCharsets.US_ASCII);
+    private static final byte[] MIC_HMAC_KEY_INFO_BYTES = "Unsigned Section HMAC key".getBytes(
+            StandardCharsets.US_ASCII);
+    private static final int AES_KEY_SIZE = 16;
+    private static final int ADV_NONCE_SIZE_SALT_DE = 16;
+    private static final int ADV_NONCE_SIZE_ENCRYPTION_INFO_DE = 12;
+    private static final int HMAC_KEY_SIZE = 32;
+
+    // Lazily instantiated when {@link #getInstance()} is called.
+    @Nullable
+    private static CryptorMicImp sCryptor;
+
+    private CryptorMicImp() {
+    }
+
+    /** Returns an instance of CryptorImpV1. */
+    public static CryptorMicImp getInstance() {
+        if (sCryptor == null) {
+            sCryptor = new CryptorMicImp();
+        }
+        return sCryptor;
+    }
+
+    /**
+     * Generate the meta data encryption key tag
+     * @param metadataEncryptionKey used as identity
+     * @param keySeed authenticity key saved in local and shared credential
+     * @return bytes generated by hmac or {@code null} when there is an error
+     */
+    @Nullable
+    public static byte[] generateMetadataEncryptionKeyTag(byte[] metadataEncryptionKey,
+            byte[] keySeed) {
+        try {
+            byte[] metadataKeyHmacKey = generateMetadataKeyHmacKey(keySeed);
+            return Cryptor.generateHmac(/* algorithm= */ HMAC_SHA256_ALGORITHM, /* input= */
+                    metadataEncryptionKey, /* key= */ metadataKeyHmacKey);
+        } catch (GeneralSecurityException e) {
+            Log.e(TAG, "Failed to generate Metadata encryption key tag.", e);
+            return null;
+        }
+    }
+
+    /**
+     * @param salt from the 2 bytes Salt Data Element
+     */
+    @Nullable
+    public static byte[] generateAdvNonce(byte[] salt) throws GeneralSecurityException {
+        return Cryptor.computeHkdf(
+                /* macAlgorithm= */ HMAC_SHA256_ALGORITHM,
+                /* ikm = */ salt,
+                /* salt= */ NP_HKDF_SALT,
+                /* info= */ ADV_NONCE_INFO_BYTES_SALT_DE,
+                /* size= */ ADV_NONCE_SIZE_SALT_DE);
+    }
+
+    /** Generates the 12 bytes nonce with salt from the 2 bytes Salt Data Element */
+    @Nullable
+    public static byte[] generateAdvNonce(byte[] salt, int deIndex)
+            throws GeneralSecurityException {
+        // go/nearby-specs-working-doc
+        // Indices are encoded as big-endian unsigned 32-bit integers, starting at 1.
+        // Index 0 is reserved
+        byte[] indexBytes = new byte[4];
+        indexBytes[3] = (byte) deIndex;
+        byte[] info =
+                ArrayUtils.concatByteArrays(ADV_NONCE_INFO_BYTES_ENCRYPTION_INFO_DE, indexBytes);
+        return Cryptor.computeHkdf(
+                /* macAlgorithm= */ HMAC_SHA256_ALGORITHM,
+                /* ikm = */ salt,
+                /* salt= */ NP_HKDF_SALT,
+                /* info= */ info,
+                /* size= */ ADV_NONCE_SIZE_ENCRYPTION_INFO_DE);
+    }
+
+    @Nullable
+    @Override
+    public byte[] encrypt(byte[] input, byte[] iv, byte[] keySeed) {
+        if (input == null || iv == null || keySeed == null) {
+            return null;
+        }
+        Cipher cipher;
+        try {
+            cipher = Cipher.getInstance(CIPHER_ALGORITHM);
+        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
+            Log.e(TAG, "Failed to encrypt with secret key.", e);
+            return null;
+        }
+
+        byte[] aesKey;
+        try {
+            aesKey = generateAesKey(keySeed);
+        } catch (GeneralSecurityException e) {
+            Log.e(TAG, "Encryption failed because failed to generate the AES key.", e);
+            return null;
+        }
+        if (aesKey == null) {
+            Log.i(TAG, "Failed to generate the AES key.");
+            return null;
+        }
+        SecretKey secretKey = new SecretKeySpec(aesKey, ENCRYPT_ALGORITHM);
+        try {
+            cipher.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(iv));
+        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
+            Log.e(TAG, "Failed to initialize cipher.", e);
+            return null;
+
+        }
+        try {
+            return cipher.doFinal(input);
+        } catch (IllegalBlockSizeException | BadPaddingException e) {
+            Log.e(TAG, "Failed to encrypt with secret key.", e);
+            return null;
+        }
+    }
+
+    @Nullable
+    @Override
+    public byte[] decrypt(byte[] encryptedData, byte[] iv, byte[] keySeed) {
+        if (encryptedData == null || iv == null || keySeed == null) {
+            return null;
+        }
+
+        Cipher cipher;
+        try {
+            cipher = Cipher.getInstance(CIPHER_ALGORITHM);
+        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
+            Log.e(TAG, "Failed to get cipher instance.", e);
+            return null;
+        }
+        byte[] aesKey;
+        try {
+            aesKey = generateAesKey(keySeed);
+        } catch (GeneralSecurityException e) {
+            Log.e(TAG, "Decryption failed because failed to generate the AES key.", e);
+            return null;
+        }
+        SecretKey secretKey = new SecretKeySpec(aesKey, ENCRYPT_ALGORITHM);
+        try {
+            cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(iv));
+        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
+            Log.e(TAG, "Failed to initialize cipher.", e);
+            return null;
+        }
+
+        try {
+            return cipher.doFinal(encryptedData);
+        } catch (IllegalBlockSizeException | BadPaddingException e) {
+            Log.e(TAG, "Failed to decrypt bytes with secret key.", e);
+            return null;
+        }
+    }
+
+    @Override
+    @Nullable
+    public byte[] sign(byte[] data, byte[] key) {
+        byte[] res = generateHmacTag(data, key);
+        return res;
+    }
+
+    @Override
+    public int getSignatureLength() {
+        return MIC_LENGTH;
+    }
+
+    @Override
+    public boolean verify(byte[] data, byte[] key, byte[] signature) {
+        return Arrays.equals(sign(data, key), signature);
+    }
+
+    /**
+     * Generates a 16 bytes HMAC tag. This is used for decryptor to verify if the computed HMAC tag
+     * is equal to HMAC tag in advertisement to see data integrity.
+     *
+     * @param input   concatenated advertisement UUID, header, section header, derived salt, and
+     *                section content
+     * @param keySeed the MIC HMAC key is calculated using the derived key
+     * @return the first 16 bytes of HMAC-SHA256 result
+     */
+    @Nullable
+    @VisibleForTesting
+    byte[] generateHmacTag(byte[] input, byte[] keySeed) {
+        try {
+            if (input == null || keySeed == null) {
+                return null;
+            }
+            byte[] micHmacKey = generateMicHmacKey(keySeed);
+            byte[] hmac = Cryptor.generateHmac(/* algorithm= */ HMAC_SHA256_ALGORITHM, /* input= */
+                    input, /* key= */ micHmacKey);
+            if (ArrayUtils.isEmpty(hmac)) {
+                return null;
+            }
+            return Arrays.copyOf(hmac, MIC_LENGTH);
+        } catch (GeneralSecurityException e) {
+            Log.e(TAG, "Failed to generate mic hmac key.", e);
+            return null;
+        }
+    }
+
+    @Nullable
+    private static byte[] generateAesKey(byte[] keySeed) throws GeneralSecurityException {
+        return Cryptor.computeHkdf(
+                /* macAlgorithm= */ HMAC_SHA256_ALGORITHM,
+                /* ikm = */ keySeed,
+                /* salt= */ NP_HKDF_SALT,
+                /* info= */ AES_KEY_INFO_BYTES,
+                /* size= */ AES_KEY_SIZE);
+    }
+
+    private static byte[] generateMetadataKeyHmacKey(byte[] keySeed)
+            throws GeneralSecurityException {
+        return generateHmacKey(keySeed, METADATA_KEY_HMAC_KEY_INFO_BYTES);
+    }
+
+    private static byte[] generateMicHmacKey(byte[] keySeed) throws GeneralSecurityException {
+        return generateHmacKey(keySeed, MIC_HMAC_KEY_INFO_BYTES);
+    }
+
+    private static byte[] generateHmacKey(byte[] keySeed, byte[] info)
+            throws GeneralSecurityException {
+        return Cryptor.computeHkdf(
+                /* macAlgorithm= */ HMAC_SHA256_ALGORITHM,
+                /* ikm = */ keySeed,
+                /* salt= */ NP_HKDF_SALT,
+                /* info= */ info,
+                /* size= */ HMAC_KEY_SIZE);
+    }
+}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/presence/EncryptionInfoTest.java b/nearby/tests/unit/src/com/android/server/nearby/presence/EncryptionInfoTest.java
index a1eb57b..6ec7c57 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/presence/EncryptionInfoTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/presence/EncryptionInfoTest.java
@@ -20,6 +20,7 @@
 
 import static org.junit.Assert.assertThrows;
 
+import com.android.server.nearby.presence.EncryptionInfo.EncodingScheme;
 import com.android.server.nearby.util.ArrayUtils;
 
 import org.junit.Test;
@@ -50,7 +51,7 @@
     public void test_getMethods_signature() {
         byte[] data = ArrayUtils.append((byte) 0b10001000, SALT);
         EncryptionInfo info = new EncryptionInfo(data);
-        assertThat(info.getEncodingScheme()).isEqualTo(EncryptionInfo.EncodingScheme.SIGNATURE);
+        assertThat(info.getEncodingScheme()).isEqualTo(EncodingScheme.SIGNATURE);
         assertThat(info.getSalt()).isEqualTo(SALT);
     }
 
@@ -58,7 +59,14 @@
     public void test_getMethods_mic() {
         byte[] data = ArrayUtils.append((byte) 0b10000000, SALT);
         EncryptionInfo info = new EncryptionInfo(data);
-        assertThat(info.getEncodingScheme()).isEqualTo(EncryptionInfo.EncodingScheme.MIC);
+        assertThat(info.getEncodingScheme()).isEqualTo(EncodingScheme.MIC);
+        assertThat(info.getSalt()).isEqualTo(SALT);
+    }
+    @Test
+    public void test_toBytes() {
+        byte[] data = EncryptionInfo.toByte(EncodingScheme.MIC, SALT);
+        EncryptionInfo info = new EncryptionInfo(data);
+        assertThat(info.getEncodingScheme()).isEqualTo(EncodingScheme.MIC);
         assertThat(info.getSalt()).isEqualTo(SALT);
     }
 }
diff --git a/nearby/tests/unit/src/com/android/server/nearby/presence/ExtendedAdvertisementTest.java b/nearby/tests/unit/src/com/android/server/nearby/presence/ExtendedAdvertisementTest.java
index 895df69..3f00a42 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/presence/ExtendedAdvertisementTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/presence/ExtendedAdvertisementTest.java
@@ -16,6 +16,8 @@
 
 package com.android.server.nearby.presence;
 
+import static com.android.server.nearby.presence.PresenceConstants.PRESENCE_UUID_BYTES;
+
 import static com.google.common.truth.Truth.assertThat;
 
 import android.nearby.BroadcastRequest;
@@ -25,19 +27,22 @@
 import android.nearby.PrivateCredential;
 import android.nearby.PublicCredential;
 
-import com.android.server.nearby.util.encryption.CryptorImpIdentityV1;
-import com.android.server.nearby.util.encryption.CryptorImpV1;
+import com.android.server.nearby.util.ArrayUtils;
+import com.android.server.nearby.util.encryption.CryptorMicImp;
 
 import org.junit.Before;
 import org.junit.Test;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
 public class ExtendedAdvertisementTest {
+    private static final int EXTENDED_ADVERTISEMENT_BYTE_LENGTH = 67;
     private static final int IDENTITY_TYPE = PresenceCredential.IDENTITY_TYPE_PRIVATE;
+    private static final int DATA_TYPE_ACTION = 6;
     private static final int DATA_TYPE_MODEL_ID = 7;
     private static final int DATA_TYPE_BLE_ADDRESS = 101;
     private static final int DATA_TYPE_PUBLIC_IDENTITY = 3;
@@ -49,18 +54,23 @@
     private static final DataElement BLE_ADDRESS_ELEMENT =
             new DataElement(DATA_TYPE_BLE_ADDRESS, BLE_ADDRESS);
 
-    private static final byte[] IDENTITY =
-            new byte[]{1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4};
+    private static final byte[] METADATA_ENCRYPTION_KEY =
+            new byte[]{-39, -55, 115, 78, -57, 40, 115, 0, -112, 86, -86, 7, -42, 68, 11, 12};
     private static final int MEDIUM_TYPE_BLE = 0;
     private static final byte[] SALT = {2, 3};
+
     private static final int PRESENCE_ACTION_1 = 1;
     private static final int PRESENCE_ACTION_2 = 2;
+    private static final DataElement PRESENCE_ACTION_DE_1 =
+            new DataElement(DATA_TYPE_ACTION, new byte[]{PRESENCE_ACTION_1});
+    private static final DataElement PRESENCE_ACTION_DE_2 =
+            new DataElement(DATA_TYPE_ACTION, new byte[]{PRESENCE_ACTION_2});
 
     private static final byte[] SECRET_ID = new byte[]{1, 2, 3, 4};
     private static final byte[] AUTHENTICITY_KEY =
             new byte[]{-97, 10, 107, -86, 25, 65, -54, -95, -72, 59, 54, 93, 9, 3, -24, -88};
     private static final byte[] PUBLIC_KEY =
-            new byte[] {
+            new byte[]{
                     48, 89, 48, 19, 6, 7, 42, -122, 72, -50, 61, 2, 1, 6, 8, 42, -122, 72, -50, 61,
                     66, 0, 4, -56, -39, -92, 69, 0, 52, 23, 67, 83, -14, 75, 52, -14, -5, -41, 48,
                     -83, 31, 42, -39, 102, -13, 22, -73, -73, 86, 30, -96, -84, -13, 4, 122, 104,
@@ -68,7 +78,7 @@
                     123, 41, -119, -25, 1, -112, 112
             };
     private static final byte[] ENCRYPTED_METADATA_BYTES =
-            new byte[] {
+            new byte[]{
                     -44, -25, -95, -124, -7, 90, 116, -8, 7, -120, -23, -22, -106, -44, -19, 61,
                     -18, 39, 29, 78, 108, -11, -39, 85, -30, 64, -99, 102, 65, 37, -42, 114, -37,
                     88, -112, 8, -75, -53, 23, -16, -104, 67, 49, 48, -53, 73, -109, 44, -23, -11,
@@ -78,23 +88,65 @@
                     -4, -46, -30, -85, -50, 100, 46, -66, -128, 7, 66, 9, 88, 95, 12, -13, 81, -91,
             };
     private static final byte[] METADATA_ENCRYPTION_KEY_TAG =
-            new byte[] {-126, -104, 1, -1, 26, -46, -68, -86};
+            new byte[]{-100, 102, -35, -99, 66, -85, -55, -58, -52, 11, -74, 102, 109, -89, 1, -34,
+                    45, 43, 107, -60, 99, -21, 28, 34, 31, -100, -96, 108, 108, -18, 107, 5};
+
+    private static final String ENCODED_ADVERTISEMENT_ENCRYPTION_INFO =
+            "2091911000DE2A89ED98474AF3E41E48487E8AEBDE90014C18BCB9F9AAC5C11A1BE00A10A5DCD2C49A74BE"
+                    + "BAF0FE72FD5053B9DF8B9976C80BE0DCE8FEE83F1BFA9A89EB176CA48EE4ED5D15C6CDAD6B9E"
+                    + "41187AA6316D7BFD8E454A53971AC00836F7AB0771FF0534050037D49C6AEB18CF9F8590E5CD"
+                    + "EE2FBC330FCDC640C63F0735B7E3F02FE61A0496EF976A158AD3455D";
+    private static final byte[] METADATA_ENCRYPTION_KEY_TAG_2 =
+            new byte[]{-54, -39, 41, 16, 61, 79, -116, 14, 94, 0, 84, 45, 26, -108, 66, -48, 124,
+                    -81, 61, 56, -98, -47, 14, -19, 116, 106, -27, 123, -81, 49, 83, -42};
+
     private static final String DEVICE_NAME = "test_device";
 
+    private static final byte[] SALT_16 =
+            ArrayUtils.stringToBytes("DE2A89ED98474AF3E41E48487E8AEBDE");
+    private static final byte[] AUTHENTICITY_KEY_2 =  ArrayUtils.stringToBytes(
+            "959D2F3CAB8EE4A2DEB0255C03762CF5D39EB919300420E75A089050FB025E20");
+    private static final byte[] METADATA_ENCRYPTION_KEY_2 =  ArrayUtils.stringToBytes(
+            "EF5E9A0867560E52AE1F05FCA7E48D29");
+
+    private static final DataElement DE1 = new DataElement(571, ArrayUtils.stringToBytes(
+            "537F96FD94E13BE589F0141145CFC0EEC4F86FBDB2"));
+    private static final DataElement DE2 = new DataElement(541, ArrayUtils.stringToBytes(
+            "D301FFB24B5B"));
+    private static final DataElement DE3 = new DataElement(51, ArrayUtils.stringToBytes(
+            "EA95F07C25B75C04E1B2B8731F6A55BA379FB141"));
+    private static final DataElement DE4 = new DataElement(729, ArrayUtils.stringToBytes(
+            "2EFD3101E2311BBB108F0A7503907EAF0C2EAAA60CDA8D33A294C4CEACE0"));
+    private static final DataElement DE5 = new DataElement(411, ArrayUtils.stringToBytes("B0"));
+
     private PresenceBroadcastRequest.Builder mBuilder;
+    private PresenceBroadcastRequest.Builder mBuilderCredentialInfo;
     private PrivateCredential mPrivateCredential;
+    private PrivateCredential mPrivateCredential2;
+
     private PublicCredential mPublicCredential;
+    private PublicCredential mPublicCredential2;
 
     @Before
     public void setUp() {
         mPrivateCredential =
-                new PrivateCredential.Builder(SECRET_ID, AUTHENTICITY_KEY, IDENTITY, DEVICE_NAME)
+                new PrivateCredential.Builder(
+                        SECRET_ID, AUTHENTICITY_KEY, METADATA_ENCRYPTION_KEY, DEVICE_NAME)
+                        .setIdentityType(PresenceCredential.IDENTITY_TYPE_PRIVATE)
+                        .build();
+        mPrivateCredential2 =
+                new PrivateCredential.Builder(
+                        SECRET_ID, AUTHENTICITY_KEY_2, METADATA_ENCRYPTION_KEY_2, DEVICE_NAME)
                         .setIdentityType(PresenceCredential.IDENTITY_TYPE_PRIVATE)
                         .build();
         mPublicCredential =
                 new PublicCredential.Builder(SECRET_ID, AUTHENTICITY_KEY, PUBLIC_KEY,
                         ENCRYPTED_METADATA_BYTES, METADATA_ENCRYPTION_KEY_TAG)
                         .build();
+        mPublicCredential2 =
+                new PublicCredential.Builder(SECRET_ID, AUTHENTICITY_KEY_2, PUBLIC_KEY,
+                        ENCRYPTED_METADATA_BYTES, METADATA_ENCRYPTION_KEY_TAG_2)
+                        .build();
         mBuilder =
                 new PresenceBroadcastRequest.Builder(Collections.singletonList(MEDIUM_TYPE_BLE),
                         SALT, mPrivateCredential)
@@ -103,6 +155,16 @@
                         .addAction(PRESENCE_ACTION_2)
                         .addExtendedProperty(new DataElement(DATA_TYPE_BLE_ADDRESS, BLE_ADDRESS))
                         .addExtendedProperty(new DataElement(DATA_TYPE_MODEL_ID, MODE_ID_DATA));
+
+        mBuilderCredentialInfo =
+                new PresenceBroadcastRequest.Builder(Collections.singletonList(MEDIUM_TYPE_BLE),
+                        SALT_16, mPrivateCredential2)
+                        .setVersion(BroadcastRequest.PRESENCE_VERSION_V1)
+                        .addExtendedProperty(DE1)
+                        .addExtendedProperty(DE2)
+                        .addExtendedProperty(DE3)
+                        .addExtendedProperty(DE4)
+                        .addExtendedProperty(DE5);
     }
 
     @Test
@@ -112,36 +174,50 @@
 
         assertThat(originalAdvertisement.getActions())
                 .containsExactly(PRESENCE_ACTION_1, PRESENCE_ACTION_2);
-        assertThat(originalAdvertisement.getIdentity()).isEqualTo(IDENTITY);
+        assertThat(originalAdvertisement.getIdentity()).isEqualTo(METADATA_ENCRYPTION_KEY);
         assertThat(originalAdvertisement.getIdentityType()).isEqualTo(IDENTITY_TYPE);
-        assertThat(originalAdvertisement.getLength()).isEqualTo(66);
         assertThat(originalAdvertisement.getVersion()).isEqualTo(
                 BroadcastRequest.PRESENCE_VERSION_V1);
         assertThat(originalAdvertisement.getSalt()).isEqualTo(SALT);
         assertThat(originalAdvertisement.getDataElements())
-                .containsExactly(MODE_ID_ADDRESS_ELEMENT, BLE_ADDRESS_ELEMENT);
+                .containsExactly(PRESENCE_ACTION_DE_1, PRESENCE_ACTION_DE_2,
+                        MODE_ID_ADDRESS_ELEMENT, BLE_ADDRESS_ELEMENT);
+        assertThat(originalAdvertisement.getLength()).isEqualTo(EXTENDED_ADVERTISEMENT_BYTE_LENGTH);
+    }
+
+    @Test
+    public void test_createFromRequest_credentialInfo() {
+        ExtendedAdvertisement originalAdvertisement = ExtendedAdvertisement.createFromRequest(
+                mBuilderCredentialInfo.build());
+
+        assertThat(originalAdvertisement.getIdentity()).isEqualTo(METADATA_ENCRYPTION_KEY_2);
+        assertThat(originalAdvertisement.getIdentityType()).isEqualTo(IDENTITY_TYPE);
+        assertThat(originalAdvertisement.getVersion()).isEqualTo(
+                BroadcastRequest.PRESENCE_VERSION_V1);
+        assertThat(originalAdvertisement.getSalt()).isEqualTo(SALT_16);
+        assertThat(originalAdvertisement.getDataElements())
+                .containsExactly(DE1, DE2, DE3, DE4, DE5);
     }
 
     @Test
     public void test_createFromRequest_encodeAndDecode() {
         ExtendedAdvertisement originalAdvertisement = ExtendedAdvertisement.createFromRequest(
                 mBuilder.build());
-
         byte[] generatedBytes = originalAdvertisement.toBytes();
-
         ExtendedAdvertisement newAdvertisement =
                 ExtendedAdvertisement.fromBytes(generatedBytes, mPublicCredential);
 
         assertThat(newAdvertisement.getActions())
                 .containsExactly(PRESENCE_ACTION_1, PRESENCE_ACTION_2);
-        assertThat(newAdvertisement.getIdentity()).isEqualTo(IDENTITY);
+        assertThat(newAdvertisement.getIdentity()).isEqualTo(METADATA_ENCRYPTION_KEY);
         assertThat(newAdvertisement.getIdentityType()).isEqualTo(IDENTITY_TYPE);
-        assertThat(newAdvertisement.getLength()).isEqualTo(66);
+        assertThat(newAdvertisement.getLength()).isEqualTo(EXTENDED_ADVERTISEMENT_BYTE_LENGTH);
         assertThat(newAdvertisement.getVersion()).isEqualTo(
                 BroadcastRequest.PRESENCE_VERSION_V1);
         assertThat(newAdvertisement.getSalt()).isEqualTo(SALT);
         assertThat(newAdvertisement.getDataElements())
-                .containsExactly(MODE_ID_ADDRESS_ELEMENT, BLE_ADDRESS_ELEMENT);
+                .containsExactly(MODE_ID_ADDRESS_ELEMENT, BLE_ADDRESS_ELEMENT,
+                        PRESENCE_ACTION_DE_1, PRESENCE_ACTION_DE_2);
     }
 
     @Test
@@ -170,45 +246,77 @@
                         .setVersion(BroadcastRequest.PRESENCE_VERSION_V1)
                         .addAction(PRESENCE_ACTION_1);
         assertThat(ExtendedAdvertisement.createFromRequest(builder2.build())).isNull();
-
-        // empty action
-        PresenceBroadcastRequest.Builder builder3 =
-                new PresenceBroadcastRequest.Builder(Collections.singletonList(MEDIUM_TYPE_BLE),
-                        SALT, mPrivateCredential)
-                        .setVersion(BroadcastRequest.PRESENCE_VERSION_V1);
-        assertThat(ExtendedAdvertisement.createFromRequest(builder3.build())).isNull();
     }
 
     @Test
-    public void test_toBytes() {
+    public void test_toBytesSalt() throws Exception {
         ExtendedAdvertisement adv = ExtendedAdvertisement.createFromRequest(mBuilder.build());
         assertThat(adv.toBytes()).isEqualTo(getExtendedAdvertisementByteArray());
     }
 
     @Test
-    public void test_fromBytes() {
+    public void test_fromBytesSalt() throws Exception {
         byte[] originalBytes = getExtendedAdvertisementByteArray();
         ExtendedAdvertisement adv =
                 ExtendedAdvertisement.fromBytes(originalBytes, mPublicCredential);
 
         assertThat(adv.getActions())
                 .containsExactly(PRESENCE_ACTION_1, PRESENCE_ACTION_2);
-        assertThat(adv.getIdentity()).isEqualTo(IDENTITY);
+        assertThat(adv.getIdentity()).isEqualTo(METADATA_ENCRYPTION_KEY);
         assertThat(adv.getIdentityType()).isEqualTo(IDENTITY_TYPE);
-        assertThat(adv.getLength()).isEqualTo(66);
+        assertThat(adv.getLength()).isEqualTo(EXTENDED_ADVERTISEMENT_BYTE_LENGTH);
         assertThat(adv.getVersion()).isEqualTo(
                 BroadcastRequest.PRESENCE_VERSION_V1);
         assertThat(adv.getSalt()).isEqualTo(SALT);
         assertThat(adv.getDataElements())
-                .containsExactly(MODE_ID_ADDRESS_ELEMENT, BLE_ADDRESS_ELEMENT);
+                .containsExactly(MODE_ID_ADDRESS_ELEMENT, BLE_ADDRESS_ELEMENT,
+                        PRESENCE_ACTION_DE_1, PRESENCE_ACTION_DE_2);
+    }
+
+    @Test
+    public void test_toBytesCredentialElement() {
+        ExtendedAdvertisement adv =
+                ExtendedAdvertisement.createFromRequest(mBuilderCredentialInfo.build());
+        assertThat(ArrayUtils.bytesToStringUppercase(adv.toBytes())).isEqualTo(
+                ENCODED_ADVERTISEMENT_ENCRYPTION_INFO);
+    }
+
+    @Test
+    public void test_fromBytesCredentialElement() {
+        ExtendedAdvertisement adv =
+                ExtendedAdvertisement.fromBytes(
+                        ArrayUtils.stringToBytes(ENCODED_ADVERTISEMENT_ENCRYPTION_INFO),
+                        mPublicCredential2);
+        assertThat(adv.getIdentity()).isEqualTo(METADATA_ENCRYPTION_KEY_2);
+        assertThat(adv.getIdentityType()).isEqualTo(IDENTITY_TYPE);
+        assertThat(adv.getVersion()).isEqualTo(BroadcastRequest.PRESENCE_VERSION_V1);
+        assertThat(adv.getSalt()).isEqualTo(SALT_16);
+        assertThat(adv.getDataElements()).containsExactly(DE1, DE2, DE3, DE4, DE5);
+    }
+
+    @Test
+    public void test_fromBytes_metadataTagNotMatched_fail() throws Exception {
+        byte[] originalBytes = getExtendedAdvertisementByteArray();
+        PublicCredential credential =
+                new PublicCredential.Builder(SECRET_ID, AUTHENTICITY_KEY, PUBLIC_KEY,
+                        ENCRYPTED_METADATA_BYTES,
+                        new byte[]{113, 90, -55, 73, 25, -9, 55, -44, 102, 44, 81, -68, 101, 21, 32,
+                                92, -107, 3, 108, 90, 28, -73, 16, 49, -95, -121, 8, -45, -27, 16,
+                                6, 108})
+                        .build();
+        ExtendedAdvertisement adv =
+                ExtendedAdvertisement.fromBytes(originalBytes, credential);
+        assertThat(adv).isNull();
     }
 
     @Test
     public void test_toString() {
         ExtendedAdvertisement adv = ExtendedAdvertisement.createFromRequest(mBuilder.build());
         assertThat(adv.toString()).isEqualTo("ExtendedAdvertisement:"
-                + "<VERSION: 1, length: 66, dataElementCount: 2, identityType: 1, "
-                + "identity: [1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4], salt: [2, 3],"
+                + "<VERSION: 1, length: " + EXTENDED_ADVERTISEMENT_BYTE_LENGTH
+                + ", dataElementCount: 4, identityType: 1, "
+                + "identity: " + Arrays.toString(METADATA_ENCRYPTION_KEY)
+                + ", salt: [2, 3],"
                 + " actions: [1, 2]>");
     }
 
@@ -222,26 +330,22 @@
         assertThat(adv.getDataElements(DATA_TYPE_PUBLIC_IDENTITY)).isEmpty();
     }
 
-    private static byte[] getExtendedAdvertisementByteArray() {
-        ByteBuffer buffer = ByteBuffer.allocate(66);
+    private static byte[] getExtendedAdvertisementByteArray() throws Exception {
+        CryptorMicImp cryptor = CryptorMicImp.getInstance();
+        ByteBuffer buffer = ByteBuffer.allocate(EXTENDED_ADVERTISEMENT_BYTE_LENGTH);
         buffer.put((byte) 0b00100000); // Header V1
-        buffer.put((byte) 0b00100000); // Salt header: length 2, type 0
+        buffer.put(
+                (byte) (EXTENDED_ADVERTISEMENT_BYTE_LENGTH - 2)); // Section header (section length)
+
         // Salt data
-        buffer.put(SALT);
+        // Salt header: length 2, type 0
+        byte[] saltBytes = ArrayUtils.concatByteArrays(new byte[]{(byte) 0b00100000}, SALT);
+        buffer.put(saltBytes);
         // Identity header: length 16, type 1 (private identity)
-        buffer.put(new byte[]{(byte) 0b10010000, (byte) 0b00000001});
-        // Identity data
-        buffer.put(CryptorImpIdentityV1.getInstance().encrypt(IDENTITY, SALT, AUTHENTICITY_KEY));
+        byte[] identityHeader = new byte[]{(byte) 0b10010000, (byte) 0b00000001};
+        buffer.put(identityHeader);
 
         ByteBuffer deBuffer = ByteBuffer.allocate(28);
-        // Action1 header: length 1, type 6
-        deBuffer.put(new byte[]{(byte) 0b00010110});
-        // Action1 data
-        deBuffer.put((byte) PRESENCE_ACTION_1);
-        // Action2 header: length 1, type 6
-        deBuffer.put(new byte[]{(byte) 0b00010110});
-        // Action2 data
-        deBuffer.put((byte) PRESENCE_ACTION_2);
         // Ble address header: length 7, type 102
         deBuffer.put(new byte[]{(byte) 0b10000111, (byte) 0b01100101});
         // Ble address data
@@ -250,11 +354,30 @@
         deBuffer.put(new byte[]{(byte) 0b10001101, (byte) 0b00000111});
         // model id data
         deBuffer.put(MODE_ID_DATA);
+        // Action1 header: length 1, type 6
+        deBuffer.put(new byte[]{(byte) 0b00010110});
+        // Action1 data
+        deBuffer.put((byte) PRESENCE_ACTION_1);
+        // Action2 header: length 1, type 6
+        deBuffer.put(new byte[]{(byte) 0b00010110});
+        // Action2 data
+        deBuffer.put((byte) PRESENCE_ACTION_2);
+        byte[] deBytes = deBuffer.array();
+        byte[] nonce = CryptorMicImp.generateAdvNonce(SALT);
+        byte[] ciphertext =
+                cryptor.encrypt(
+                        ArrayUtils.concatByteArrays(METADATA_ENCRYPTION_KEY, deBytes),
+                        nonce, AUTHENTICITY_KEY);
+        buffer.put(ciphertext);
 
-        byte[] data = deBuffer.array();
-        CryptorImpV1 cryptor = CryptorImpV1.getInstance();
-        buffer.put(cryptor.encrypt(data, SALT, AUTHENTICITY_KEY));
-        buffer.put(cryptor.sign(data, AUTHENTICITY_KEY));
+        byte[] dataToSign = ArrayUtils.concatByteArrays(
+                PRESENCE_UUID_BYTES, /* UUID */
+                new byte[]{(byte) 0b00100000}, /* header */
+                new byte[]{(byte) (EXTENDED_ADVERTISEMENT_BYTE_LENGTH - 2)} /* sectionHeader */,
+                saltBytes, /* salt */
+                nonce, identityHeader, ciphertext);
+        byte[] mic = cryptor.sign(dataToSign, AUTHENTICITY_KEY);
+        buffer.put(mic);
 
         return buffer.array();
     }
diff --git a/nearby/tests/unit/src/com/android/server/nearby/util/ArrayUtilsTest.java b/nearby/tests/unit/src/com/android/server/nearby/util/ArrayUtilsTest.java
index a759baf..455c432 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/util/ArrayUtilsTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/util/ArrayUtilsTest.java
@@ -18,8 +18,6 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
-import androidx.test.filters.SdkSuppress;
-
 import org.junit.Test;
 
 public final class ArrayUtilsTest {
@@ -30,51 +28,58 @@
     private static final byte[] BYTES_ALL = new byte[] {7, 9, 8};
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testConcatByteArraysNoInput() {
         assertThat(ArrayUtils.concatByteArrays().length).isEqualTo(0);
     }
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testConcatByteArraysOneEmptyArray() {
         assertThat(ArrayUtils.concatByteArrays(BYTES_EMPTY).length).isEqualTo(0);
     }
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testConcatByteArraysOneNonEmptyArray() {
         assertThat(ArrayUtils.concatByteArrays(BYTES_ONE)).isEqualTo(BYTES_ONE);
     }
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testConcatByteArraysMultipleNonEmptyArrays() {
         assertThat(ArrayUtils.concatByteArrays(BYTES_ONE, BYTES_TWO)).isEqualTo(BYTES_ALL);
     }
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testConcatByteArraysMultipleArrays() {
         assertThat(ArrayUtils.concatByteArrays(BYTES_ONE, BYTES_EMPTY, BYTES_TWO))
                 .isEqualTo(BYTES_ALL);
     }
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testIsEmptyNull_returnsTrue() {
         assertThat(ArrayUtils.isEmpty(null)).isTrue();
     }
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testIsEmpty_returnsTrue() {
         assertThat(ArrayUtils.isEmpty(new byte[]{})).isTrue();
     }
 
     @Test
-    @SdkSuppress(minSdkVersion = 32, codeName = "T")
     public void testIsEmpty_returnsFalse() {
         assertThat(ArrayUtils.isEmpty(BYTES_ALL)).isFalse();
     }
+
+    @Test
+    public void testAppendByte() {
+        assertThat(ArrayUtils.append((byte) 2, BYTES_ONE)).isEqualTo(new byte[]{2, 7, 9});
+    }
+
+    @Test
+    public void testAppendByteNull() {
+        assertThat(ArrayUtils.append((byte) 2, null)).isEqualTo(new byte[]{2});
+    }
+
+    @Test
+    public void testAppendByteToArray() {
+        assertThat(ArrayUtils.append(BYTES_ONE, (byte) 2)).isEqualTo(new byte[]{7, 9, 2});
+    }
 }
diff --git a/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorImpIdentityV1Test.java b/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorImpIdentityV1Test.java
deleted file mode 100644
index f0294fc..0000000
--- a/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorImpIdentityV1Test.java
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * Copyright (C) 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.android.server.nearby.util.encryption;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import android.util.Log;
-
-import org.junit.Test;
-
-import java.util.Arrays;
-
-public class CryptorImpIdentityV1Test {
-    private static final String TAG = "CryptorImpIdentityV1Test";
-    private static final byte[] SALT = new byte[] {102, 22};
-    private static final byte[] DATA =
-            new byte[] {107, -102, 101, 107, 20, 62, 2, 73, 113, 59, 8, -14, -58, 122};
-    private static final byte[] AUTHENTICITY_KEY =
-            new byte[] {-89, 88, -50, -42, -99, 57, 84, -24, 121, 1, -104, -8, -26, -73, -36, 100};
-
-    @Test
-    public void test_encrypt_decrypt() {
-        Cryptor identityCryptor = CryptorImpIdentityV1.getInstance();
-        byte[] encryptedData = identityCryptor.encrypt(DATA, SALT, AUTHENTICITY_KEY);
-
-        assertThat(identityCryptor.decrypt(encryptedData, SALT, AUTHENTICITY_KEY)).isEqualTo(DATA);
-    }
-
-    @Test
-    public void test_encryption() {
-        Cryptor identityCryptor = CryptorImpIdentityV1.getInstance();
-        byte[] encryptedData = identityCryptor.encrypt(DATA, SALT, AUTHENTICITY_KEY);
-
-        // for debugging
-        Log.d(TAG, "encrypted data is: " + Arrays.toString(encryptedData));
-
-        assertThat(encryptedData).isEqualTo(getEncryptedData());
-    }
-
-    @Test
-    public void test_decryption() {
-        Cryptor identityCryptor = CryptorImpIdentityV1.getInstance();
-        byte[] decryptedData =
-                identityCryptor.decrypt(getEncryptedData(), SALT, AUTHENTICITY_KEY);
-        // for debugging
-        Log.d(TAG, "decrypted data is: " + Arrays.toString(decryptedData));
-
-        assertThat(decryptedData).isEqualTo(DATA);
-    }
-
-    @Test
-    public void generateHmacTag() {
-        CryptorImpIdentityV1 identityCryptor = CryptorImpIdentityV1.getInstance();
-        byte[] generatedTag = identityCryptor.sign(DATA);
-        byte[] expectedTag = new byte[]{50, 116, 95, -87, 63, 123, -79, -43};
-        assertThat(generatedTag).isEqualTo(expectedTag);
-    }
-
-    private static byte[] getEncryptedData() {
-        return new byte[]{6, -31, -32, -123, 43, -92, -47, -110, -65, 126, -15, -51, -19, -43};
-    }
-}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorImpV1Test.java b/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorImpV1Test.java
deleted file mode 100644
index 3ca2575..0000000
--- a/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorImpV1Test.java
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- * Copyright (C) 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.android.server.nearby.util.encryption;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import android.util.Log;
-
-import org.junit.Test;
-
-import java.util.Arrays;
-
-/**
- * Unit test for {@link CryptorImpV1}
- */
-public final class CryptorImpV1Test {
-    private static final String TAG = "CryptorImpV1Test";
-    private static final byte[] SALT = new byte[] {102, 22};
-    private static final byte[] DATA =
-            new byte[] {107, -102, 101, 107, 20, 62, 2, 73, 113, 59, 8, -14, -58, 122};
-    private static final byte[] AUTHENTICITY_KEY =
-            new byte[] {-89, 88, -50, -42, -99, 57, 84, -24, 121, 1, -104, -8, -26, -73, -36, 100};
-
-    @Test
-    public void test_encryption() {
-        Cryptor v1Cryptor = CryptorImpV1.getInstance();
-        byte[] encryptedData = v1Cryptor.encrypt(DATA, SALT, AUTHENTICITY_KEY);
-
-        // for debugging
-        Log.d(TAG, "encrypted data is: " + Arrays.toString(encryptedData));
-
-        assertThat(encryptedData).isEqualTo(getEncryptedData());
-    }
-
-    @Test
-    public void test_encryption_invalidInput() {
-        Cryptor v1Cryptor = CryptorImpV1.getInstance();
-        assertThat(v1Cryptor.encrypt(DATA, SALT, new byte[]{1, 2, 3, 4, 6})).isNull();
-    }
-
-    @Test
-    public void test_decryption() {
-        Cryptor v1Cryptor = CryptorImpV1.getInstance();
-        byte[] decryptedData =
-                v1Cryptor.decrypt(getEncryptedData(), SALT, AUTHENTICITY_KEY);
-        // for debugging
-        Log.d(TAG, "decrypted data is: " + Arrays.toString(decryptedData));
-
-        assertThat(decryptedData).isEqualTo(DATA);
-    }
-
-    @Test
-    public void test_decryption_invalidInput() {
-        Cryptor v1Cryptor = CryptorImpV1.getInstance();
-        assertThat(v1Cryptor.decrypt(getEncryptedData(), SALT, new byte[]{1, 2, 3, 4, 6})).isNull();
-    }
-
-    @Test
-    public void generateSign() {
-        CryptorImpV1 v1Cryptor = CryptorImpV1.getInstance();
-        byte[] generatedTag = v1Cryptor.sign(DATA, AUTHENTICITY_KEY);
-        byte[] expectedTag = new byte[]{
-                100, 88, -104, 80, -66, 107, -38, 95, 34, 40, -56, -23, -90, 90, -87, 12};
-        assertThat(generatedTag).isEqualTo(expectedTag);
-    }
-
-    @Test
-    public void test_verify() {
-        CryptorImpV1 v1Cryptor = CryptorImpV1.getInstance();
-        byte[] expectedTag = new byte[]{
-                100, 88, -104, 80, -66, 107, -38, 95, 34, 40, -56, -23, -90, 90, -87, 12};
-
-        assertThat(v1Cryptor.verify(DATA, AUTHENTICITY_KEY, expectedTag)).isTrue();
-        assertThat(v1Cryptor.verify(DATA, AUTHENTICITY_KEY, DATA)).isFalse();
-    }
-
-    @Test
-    public void test_generateHmacTag_sameResult() {
-        CryptorImpV1 v1Cryptor = CryptorImpV1.getInstance();
-        byte[] res1 = v1Cryptor.generateHmacTag(DATA, AUTHENTICITY_KEY);
-        assertThat(res1)
-                .isEqualTo(v1Cryptor.generateHmacTag(DATA, AUTHENTICITY_KEY));
-    }
-
-    @Test
-    public void test_generateHmacTag_nullData() {
-        CryptorImpV1 v1Cryptor = CryptorImpV1.getInstance();
-        assertThat(v1Cryptor.generateHmacTag(/* data= */ null, AUTHENTICITY_KEY)).isNull();
-    }
-
-    @Test
-    public void test_generateHmacTag_nullKey() {
-        CryptorImpV1 v1Cryptor = CryptorImpV1.getInstance();
-        assertThat(v1Cryptor.generateHmacTag(DATA, /* authenticityKey= */ null)).isNull();
-    }
-
-    private static byte[] getEncryptedData() {
-        return new byte[]{-92, 94, -99, -97, 81, -48, -7, 119, -64, -22, 45, -49, -50, 92};
-    }
-}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorMicImpTest.java b/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorMicImpTest.java
new file mode 100644
index 0000000..b6d2333
--- /dev/null
+++ b/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorMicImpTest.java
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.util.encryption;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+/**
+ * Unit test for {@link CryptorMicImp}
+ */
+public final class CryptorMicImpTest {
+    private static final String TAG = "CryptorImpV1Test";
+    private static final byte[] SALT = new byte[]{102, 22};
+    private static final byte[] DATA =
+            new byte[]{107, -102, 101, 107, 20, 62, 2, 73, 113, 59, 8, -14, -58, 122};
+    private static final byte[] AUTHENTICITY_KEY =
+            new byte[]{-89, 88, -50, -42, -99, 57, 84, -24, 121, 1, -104, -8, -26, -73, -36, 100};
+
+    private static byte[] getEncryptedData() {
+        return new byte[]{112, 23, -111, 87, 122, -27, 45, -25, -35, 84, -89, 115, 61, 113};
+    }
+
+    @Test
+    public void test_encryption() throws Exception {
+        Cryptor v1Cryptor = CryptorMicImp.getInstance();
+        byte[] encryptedData =
+                v1Cryptor.encrypt(DATA,  CryptorMicImp.generateAdvNonce(SALT), AUTHENTICITY_KEY);
+        assertThat(encryptedData).isEqualTo(getEncryptedData());
+    }
+
+    @Test
+    public void test_decryption() throws Exception {
+        Cryptor v1Cryptor = CryptorMicImp.getInstance();
+        byte[] decryptedData =
+                v1Cryptor.decrypt(getEncryptedData(), CryptorMicImp.generateAdvNonce(SALT),
+                        AUTHENTICITY_KEY);
+        assertThat(decryptedData).isEqualTo(DATA);
+    }
+
+    @Test
+    public void test_verify() {
+        CryptorMicImp v1Cryptor = CryptorMicImp.getInstance();
+        byte[] expectedTag = new byte[]{
+                -80, -51, -101, -7, -65, 110, 37, 68, 122, -128, 57, -90, -115, -59, -61, 46};
+        assertThat(v1Cryptor.verify(DATA, AUTHENTICITY_KEY, expectedTag)).isTrue();
+        assertThat(v1Cryptor.verify(DATA, AUTHENTICITY_KEY, DATA)).isFalse();
+    }
+
+    @Test
+    public void test_generateHmacTag_sameResult() {
+        CryptorMicImp v1Cryptor = CryptorMicImp.getInstance();
+        byte[] res1 = v1Cryptor.generateHmacTag(DATA, AUTHENTICITY_KEY);
+        assertThat(res1)
+                .isEqualTo(v1Cryptor.generateHmacTag(DATA, AUTHENTICITY_KEY));
+    }
+
+    @Test
+    public void test_generateHmacTag_nullData() {
+        CryptorMicImp v1Cryptor = CryptorMicImp.getInstance();
+        assertThat(v1Cryptor.generateHmacTag(/* data= */ null, AUTHENTICITY_KEY)).isNull();
+    }
+
+    @Test
+    public void test_generateHmacTag_nullKey() {
+        CryptorMicImp v1Cryptor = CryptorMicImp.getInstance();
+        assertThat(v1Cryptor.generateHmacTag(DATA, /* authenticityKey= */ null)).isNull();
+    }
+}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorTest.java b/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorTest.java
index ca612e3..1fb2236 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/util/encryption/CryptorTest.java
@@ -42,7 +42,7 @@
         assertThat(res2).hasLength(outputSize);
         assertThat(res1).isNotEqualTo(res2);
         assertThat(res1)
-                .isEqualTo(CryptorImpV1.computeHkdf(DATA, AUTHENTICITY_KEY, outputSize));
+                .isEqualTo(CryptorMicImp.computeHkdf(DATA, AUTHENTICITY_KEY, outputSize));
     }
 
     @Test
diff --git a/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java b/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
index 111e0ba..781a04e 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
@@ -142,6 +142,7 @@
                 return (NetlinkMessage) RtNetlinkAddressMessage.parse(nlmsghdr, byteBuffer);
             case NetlinkConstants.RTM_NEWROUTE:
             case NetlinkConstants.RTM_DELROUTE:
+            case NetlinkConstants.RTM_GETROUTE:
                 return (NetlinkMessage) RtNetlinkRouteMessage.parse(nlmsghdr, byteBuffer);
             case NetlinkConstants.RTM_NEWNEIGH:
             case NetlinkConstants.RTM_DELNEIGH:
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
index ff37639..5272366 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
@@ -71,13 +71,17 @@
             }
             sb.append("NLM_F_ECHO");
         }
-        if ((flags & NLM_F_ROOT) != 0) {
+        if ((flags & NLM_F_DUMP) == NLM_F_DUMP) {
+            if (sb.length() > 0) {
+                sb.append("|");
+            }
+            sb.append("NLM_F_DUMP");
+        } else if ((flags & NLM_F_ROOT) != 0) { // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH
             if (sb.length() > 0) {
                 sb.append("|");
             }
             sb.append("NLM_F_ROOT");
-        }
-        if ((flags & NLM_F_MATCH) != 0) {
+        } else if ((flags & NLM_F_MATCH) != 0) {
             if (sb.length() > 0) {
                 sb.append("|");
             }
diff --git a/staticlibs/tests/unit/Android.bp b/staticlibs/tests/unit/Android.bp
index 031e52f..0dfca57 100644
--- a/staticlibs/tests/unit/Android.bp
+++ b/staticlibs/tests/unit/Android.bp
@@ -33,7 +33,10 @@
         "//packages/modules/Connectivity/Tethering/tests:__subpackages__",
         "//packages/modules/NetworkStack/tests/integration",
     ],
-    lint: { strict_updatability_linting: true },
+    lint: {
+        strict_updatability_linting: true,
+        test: true
+    },
 }
 
 android_test {
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
index b7f68c6..a0d8b8c 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
@@ -16,6 +16,7 @@
 
 package com.android.net.module.util.netlink;
 
+import static com.android.net.module.util.netlink.StructNlMsgHdr.NLM_F_DUMP;
 import static org.junit.Assert.fail;
 
 import android.system.OsConstants;
@@ -48,10 +49,14 @@
     public static final String TEST_NLMSG_PID_STR = "nlmsg_pid{5678}";
 
     private StructNlMsgHdr makeStructNlMsgHdr(short type) {
+        return makeStructNlMsgHdr(type, TEST_NLMSG_FLAGS);
+    }
+
+    private StructNlMsgHdr makeStructNlMsgHdr(short type, short flags) {
         final StructNlMsgHdr struct = new StructNlMsgHdr();
         struct.nlmsg_len = TEST_NLMSG_LEN;
         struct.nlmsg_type = type;
-        struct.nlmsg_flags = TEST_NLMSG_FLAGS;
+        struct.nlmsg_flags = flags;
         struct.nlmsg_seq = TEST_NLMSG_SEQ;
         struct.nlmsg_pid = TEST_NLMSG_PID;
         return struct;
@@ -62,6 +67,11 @@
         fail("\"" + actualValue + "\" does not contain \"" + expectedSubstring + "\"");
     }
 
+    private static void assertNotContains(String actualValue, String unexpectedSubstring) {
+        if (!actualValue.contains(unexpectedSubstring)) return;
+        fail("\"" + actualValue + "\" contains \"" + unexpectedSubstring + "\"");
+    }
+
     @Test
     public void testToString() {
         StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_NEWADDR);
@@ -99,4 +109,31 @@
         assertContains(s, TEST_NLMSG_PID_STR);
         assertContains(s, "nlmsg_type{20(SOCK_DIAG_BY_FAMILY)}");
     }
+
+    @Test
+    public void testToString_flags_dumpRequest() {
+        final short flags = StructNlMsgHdr.NLM_F_REQUEST | StructNlMsgHdr.NLM_F_DUMP;
+        StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_GETROUTE, flags);
+
+        String s = struct.toString(OsConstants.NETLINK_ROUTE);
+
+        assertContains(s, "RTM_GETROUTE");
+        assertContains(s, "NLM_F_REQUEST");
+        assertContains(s, "NLM_F_DUMP");
+        // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH;
+        assertNotContains(s, "NLM_F_MATCH");
+        assertNotContains(s, "NLM_F_ROOT");
+    }
+
+    @Test
+    public void testToString_flags_root() {
+        final short flags = StructNlMsgHdr.NLM_F_ROOT;
+        StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_GETROUTE, flags);
+
+        String s = struct.toString(OsConstants.NETLINK_ROUTE);
+
+        assertContains(s, "NLM_F_ROOT");
+        // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH;
+        assertNotContains(s, "NLM_F_DUMP");
+    }
 }
diff --git a/tests/unit/java/com/android/server/connectivity/VpnTest.java b/tests/unit/java/com/android/server/connectivity/VpnTest.java
index 46e9e45..c9cece0 100644
--- a/tests/unit/java/com/android/server/connectivity/VpnTest.java
+++ b/tests/unit/java/com/android/server/connectivity/VpnTest.java
@@ -2979,7 +2979,7 @@
                         null /* iface */, RTN_UNREACHABLE));
         assertEquals(expectedRoutes, lp.getRoutes());
 
-        verify(mMockNetworkAgent).unregister();
+        verify(mMockNetworkAgent, timeout(TEST_TIMEOUT_MS)).unregister();
     }
 
     @Test