diff --git a/core/java/android/app/RemoteLockscreenValidationResult.aidl b/core/java/android/app/RemoteLockscreenValidationResult.aidl
new file mode 100644
index 0000000..504f78f
--- /dev/null
+++ b/core/java/android/app/RemoteLockscreenValidationResult.aidl
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2023 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 android.app;
+
+/** {@hide} */
+parcelable RemoteLockscreenValidationResult;
diff --git a/core/java/android/app/RemoteLockscreenValidationResult.java b/core/java/android/app/RemoteLockscreenValidationResult.java
new file mode 100644
index 0000000..4f15be2
--- /dev/null
+++ b/core/java/android/app/RemoteLockscreenValidationResult.java
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2023 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 android.app;
+
+import android.annotation.DurationMillisLong;
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+/**
+ * Result of lock screen credentials verification.
+ *
+ * @hide
+ */
+public final class RemoteLockscreenValidationResult implements Parcelable {
+
+    /**
+     * The guess was correct
+     */
+    public static final int RESULT_GUESS_VALID = 1;
+
+    /**
+     * Remote device provided incorrect credentials.
+     */
+    public static final int RESULT_GUESS_INVALID = 2;
+
+    /**
+     * The operation was canceled because the API is locked out due to too many attempts. It
+     * usually happens after 5 failed attempts and API may be called again after a short
+     * delay specified by {@code getTimeoutMillis}.
+     */
+    public static final int RESULT_LOCKOUT = 3;
+
+    /**
+     * There were too many invalid guesses.
+     */
+    public static final int RESULT_NO_REMAINING_ATTEMPTS = 4;
+
+    @IntDef({RESULT_GUESS_VALID,
+            RESULT_GUESS_INVALID,
+            RESULT_LOCKOUT,
+            RESULT_NO_REMAINING_ATTEMPTS})
+    @Retention(RetentionPolicy.SOURCE)
+    @interface ResultCode {}
+
+    private int mResultCode;
+    private long mTimeoutMillis;
+
+    public static final @NonNull Parcelable.Creator<RemoteLockscreenValidationResult> CREATOR =
+            new Parcelable.Creator<RemoteLockscreenValidationResult>() {
+        @Override
+        public RemoteLockscreenValidationResult createFromParcel(Parcel source) {
+            return new RemoteLockscreenValidationResult(source);
+        }
+
+        @Override
+        public RemoteLockscreenValidationResult[] newArray(int size) {
+            return new RemoteLockscreenValidationResult[size];
+        }
+    };
+
+    /**
+     * Builder for {@code RemoteLockscreenValidationResult}
+     */
+    public static final class Builder {
+        private RemoteLockscreenValidationResult mInstance = new RemoteLockscreenValidationResult();
+
+        /**
+         * Sets the result code.
+         */
+        public @NonNull Builder setResultCode(@ResultCode int resultCode) {
+            mInstance.mResultCode = resultCode;
+            return this;
+        }
+
+        /**
+         * Sets timeout for {@code RESULT_LOCKOUT}.
+         * Default value is {@code 0}.
+         */
+        public @NonNull Builder setTimeoutMillis(@DurationMillisLong long timeoutMillis) {
+            mInstance.mTimeoutMillis = timeoutMillis;
+            return this;
+        }
+
+        /**
+         * Creates {@code RemoteLockscreenValidationResult}.
+         *
+         * @throws IllegalStateException if result code was not set.
+         */
+        public @NonNull RemoteLockscreenValidationResult build() {
+            if (mInstance.mResultCode == 0) {
+                throw new IllegalStateException("Result code must be set");
+            }
+            return mInstance;
+        }
+    }
+
+    /**
+     * Gets the result code.
+     */
+    public @ResultCode int getResultCode() {
+        return mResultCode;
+    }
+
+    /**
+     * Delay before next attempt to verify credentials.
+     *
+     * Default value is {@code 0}.
+     */
+    public @DurationMillisLong long getTimeoutMillis() {
+        return mTimeoutMillis;
+    }
+
+
+    @Override
+    public void writeToParcel(@NonNull Parcel out, int flags) {
+        out.writeInt(mResultCode);
+        out.writeLong(mTimeoutMillis);
+    }
+
+    private RemoteLockscreenValidationResult() {
+    }
+
+    private RemoteLockscreenValidationResult(Parcel in) {
+        mResultCode = in.readInt();
+        mTimeoutMillis = in.readLong();
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+}
diff --git a/core/java/android/app/StartLockscreenValidationRequest.aidl b/core/java/android/app/StartLockscreenValidationRequest.aidl
new file mode 100644
index 0000000..367dfee
--- /dev/null
+++ b/core/java/android/app/StartLockscreenValidationRequest.aidl
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2023 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 android.app;
+
+/** {@hide} */
+parcelable StartLockscreenValidationRequest;
diff --git a/core/java/android/app/StartLockscreenValidationRequest.java b/core/java/android/app/StartLockscreenValidationRequest.java
new file mode 100644
index 0000000..69c268bcb
--- /dev/null
+++ b/core/java/android/app/StartLockscreenValidationRequest.java
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2023 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 android.app;
+
+import android.annotation.NonNull;
+import android.app.KeyguardManager.LockTypes;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import java.util.Objects;
+
+/**
+ * Provides information necessary to perform remote lock screen credentials check.
+ *
+ * @hide
+ */
+public final class StartLockscreenValidationRequest implements Parcelable {
+
+    @LockTypes
+    private int mLockscreenUiType;
+
+    private byte[] mSourcePublicKey;
+
+    private int mRemainingAttempts;
+
+    public static final @NonNull Parcelable.Creator<StartLockscreenValidationRequest> CREATOR = new
+            Parcelable.Creator<StartLockscreenValidationRequest>() {
+        @Override
+        public StartLockscreenValidationRequest createFromParcel(Parcel source) {
+            return new StartLockscreenValidationRequest(source);
+        }
+
+        @Override
+        public StartLockscreenValidationRequest[] newArray(int size) {
+            return new StartLockscreenValidationRequest[size];
+        }
+    };
+
+
+    /**
+     * Builder for {@code StartLockscreenValidationRequest}
+     */
+    public static final class Builder {
+        private StartLockscreenValidationRequest mInstance = new StartLockscreenValidationRequest();
+
+        /**
+         * Sets UI type.
+         * Default value is {@code LockTypes.PASSWORD}
+         *
+         * @param lockscreenUiType The UI format
+         * @return This builder.
+         */
+        public @NonNull Builder setLockscreenUiType(@LockTypes int lockscreenUiType) {
+            mInstance.mLockscreenUiType = lockscreenUiType;
+            return this;
+        }
+
+        /**
+         * Sets public key using secure box encoding
+         * @return This builder.
+         */
+        public @NonNull Builder setSourcePublicKey(@NonNull byte[] publicKey) {
+            mInstance.mSourcePublicKey = publicKey;
+            return this;
+        }
+
+        /**
+         * Sets the number of remaining credentials check
+         * Default value is {@code 0}
+         *
+         * @return This builder.
+         */
+        public @NonNull Builder setRemainingAttempts(int remainingAttempts) {
+            mInstance.mRemainingAttempts = remainingAttempts;
+            return this;
+        }
+
+        /**
+         * Creates {@code StartLockscreenValidationRequest}
+         *
+         * @throws NullPointerException if required fields are not set.
+         */
+        public @NonNull StartLockscreenValidationRequest build() {
+            Objects.requireNonNull(mInstance.mSourcePublicKey);
+            return mInstance;
+        }
+    }
+
+    /**
+     * Specifies lock screen credential type.
+     */
+    public @LockTypes int getLockscreenUiType() {
+        return mLockscreenUiType;
+    }
+
+    /**
+     * Public key used to send encrypted credentials.
+     */
+    public @NonNull byte[] getSourcePublicKey() {
+        return mSourcePublicKey;
+    }
+
+    /**
+     * Number of remaining attempts to verify credentials.
+     *
+     * <p>After correct guess counter is reset to {@code 5}.
+     */
+    public int getRemainingAttempts() {
+        return mRemainingAttempts;
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel out, int flags) {
+        out.writeInt(mLockscreenUiType);
+        out.writeByteArray(mSourcePublicKey);
+        out.writeInt(mRemainingAttempts);
+    }
+
+    private StartLockscreenValidationRequest() {
+    }
+
+    private StartLockscreenValidationRequest(Parcel in) {
+        mLockscreenUiType = in.readInt();
+        mSourcePublicKey = in.createByteArray();
+        mRemainingAttempts = in.readInt();
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+}
diff --git a/services/core/java/com/android/server/locksettings/LockSettingsService.java b/services/core/java/com/android/server/locksettings/LockSettingsService.java
index 48e0c30..a88925a 100644
--- a/services/core/java/com/android/server/locksettings/LockSettingsService.java
+++ b/services/core/java/com/android/server/locksettings/LockSettingsService.java
@@ -56,6 +56,8 @@
 import android.app.Notification;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
+import android.app.RemoteLockscreenValidationResult;
+import android.app.StartLockscreenValidationRequest;
 import android.app.admin.DevicePolicyManager;
 import android.app.admin.DevicePolicyManagerInternal;
 import android.app.admin.DeviceStateCache;
@@ -114,7 +116,6 @@
 import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.EventLog;
-import android.util.FeatureFlagUtils;
 import android.util.LongSparseArray;
 import android.util.Slog;
 import android.util.SparseArray;
@@ -2507,23 +2508,18 @@
     /**
      * Starts a session to verify lock screen credentials provided by a remote device.
      */
-    public void startRemoteLockscreenValidation() {
-        if (!FeatureFlagUtils.isEnabled(mContext,
-                FeatureFlagUtils.SETTINGS_ENABLE_LOCKSCREEN_TRANSFER_API)) {
-            throw new UnsupportedOperationException("Under development");
-        }
-        mRecoverableKeyStoreManager.startRemoteLockscreenValidation();
+    @NonNull
+    public StartLockscreenValidationRequest startRemoteLockscreenValidation() {
+        return mRecoverableKeyStoreManager.startRemoteLockscreenValidation(this);
     }
 
     /**
-     * Verifies credentials guess from a remote device.
+     * Verifies encrypted credentials guess from a remote device.
      */
-    public void validateRemoteLockscreen(@NonNull byte[] encryptedCredential) {
-        if (!FeatureFlagUtils.isEnabled(mContext,
-                FeatureFlagUtils.SETTINGS_ENABLE_LOCKSCREEN_TRANSFER_API)) {
-            throw new UnsupportedOperationException("Under development");
-        }
-        mRecoverableKeyStoreManager.validateRemoteLockscreen(encryptedCredential);
+    @NonNull
+    public RemoteLockscreenValidationResult
+            validateRemoteLockScreen2(@NonNull byte[] encryptedCredential) {
+        return mRecoverableKeyStoreManager.validateRemoteLockscreen(encryptedCredential, this);
     }
 
     // Reading these settings needs the contacts permission
diff --git a/services/core/java/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManager.java b/services/core/java/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManager.java
index b437421..d981569 100644
--- a/services/core/java/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManager.java
+++ b/services/core/java/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManager.java
@@ -28,7 +28,10 @@
 import android.Manifest;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.app.KeyguardManager;
 import android.app.PendingIntent;
+import android.app.RemoteLockscreenValidationResult;
+import android.app.StartLockscreenValidationRequest;
 import android.content.Context;
 import android.os.Binder;
 import android.os.RemoteException;
@@ -40,11 +43,14 @@
 import android.security.keystore.recovery.RecoveryController;
 import android.security.keystore.recovery.WrappedApplicationKey;
 import android.util.ArrayMap;
+import android.util.FeatureFlagUtils;
 import android.util.Log;
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.HexDump;
+import com.android.internal.widget.LockPatternUtils;
 import com.android.security.SecureBox;
+import com.android.server.locksettings.LockSettingsService;
 import com.android.server.locksettings.recoverablekeystore.certificate.CertParsingException;
 import com.android.server.locksettings.recoverablekeystore.certificate.CertUtils;
 import com.android.server.locksettings.recoverablekeystore.certificate.CertValidationException;
@@ -55,6 +61,8 @@
 import com.android.server.locksettings.recoverablekeystore.storage.RecoverableKeyStoreDb;
 import com.android.server.locksettings.recoverablekeystore.storage.RecoverySessionStorage;
 import com.android.server.locksettings.recoverablekeystore.storage.RecoverySnapshotStorage;
+import com.android.server.locksettings.recoverablekeystore.storage.RemoteLockscreenValidationSessionStorage;
+import com.android.server.locksettings.recoverablekeystore.storage.RemoteLockscreenValidationSessionStorage.LockscreenVerificationSession;
 
 import java.io.IOException;
 import java.security.InvalidKeyException;
@@ -103,6 +111,9 @@
     private final ApplicationKeyStorage mApplicationKeyStorage;
     private final TestOnlyInsecureCertificateHelper mTestCertHelper;
     private final CleanupManager mCleanupManager;
+    // only set if SETTINGS_ENABLE_LOCKSCREEN_TRANSFER_API is enabled.
+    @Nullable private final RemoteLockscreenValidationSessionStorage
+            mRemoteLockscreenValidationSessionStorage;
 
     /**
      * Returns a new or existing instance.
@@ -112,7 +123,18 @@
     public static synchronized RecoverableKeyStoreManager
             getInstance(Context context) {
         if (mInstance == null) {
-            RecoverableKeyStoreDb db = RecoverableKeyStoreDb.newInstance(context);
+            RecoverableKeyStoreDb db;
+            RemoteLockscreenValidationSessionStorage lockscreenCheckSessions;
+            if (FeatureFlagUtils.isEnabled(context,
+                    FeatureFlagUtils.SETTINGS_ENABLE_LOCKSCREEN_TRANSFER_API)) {
+                // TODO(b/254335492): Remove flag check when feature is launched.
+                db = RecoverableKeyStoreDb.newInstance(context, 7);
+                lockscreenCheckSessions = new RemoteLockscreenValidationSessionStorage();
+            } else {
+                db = RecoverableKeyStoreDb.newInstance(context);
+                lockscreenCheckSessions = null;
+            }
+
             PlatformKeyManager platformKeyManager;
             ApplicationKeyStorage applicationKeyStorage;
             try {
@@ -142,7 +164,8 @@
                     platformKeyManager,
                     applicationKeyStorage,
                     new TestOnlyInsecureCertificateHelper(),
-                    cleanupManager);
+                    cleanupManager,
+                    lockscreenCheckSessions);
         }
         return mInstance;
     }
@@ -158,7 +181,8 @@
             PlatformKeyManager platformKeyManager,
             ApplicationKeyStorage applicationKeyStorage,
             TestOnlyInsecureCertificateHelper testOnlyInsecureCertificateHelper,
-            CleanupManager cleanupManager) {
+            CleanupManager cleanupManager,
+            RemoteLockscreenValidationSessionStorage remoteLockscreenValidationSessionStorage) {
         mContext = context;
         mDatabase = recoverableKeyStoreDb;
         mRecoverySessionStorage = recoverySessionStorage;
@@ -177,6 +201,7 @@
             Log.wtf(TAG, "AES keygen algorithm not available. AOSP must support this.", e);
             throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage());
         }
+        mRemoteLockscreenValidationSessionStorage = remoteLockscreenValidationSessionStorage;
     }
 
     /**
@@ -969,19 +994,50 @@
     /**
      * Starts a session to verify lock screen credentials provided by a remote device.
      */
-    public void startRemoteLockscreenValidation() {
+    public StartLockscreenValidationRequest startRemoteLockscreenValidation(
+            LockSettingsService lockSettingService) {
+        if (mRemoteLockscreenValidationSessionStorage == null) {
+            throw new UnsupportedOperationException("Under development");
+        }
         checkVerifyRemoteLockscreenPermission();
-        // TODO(b/254335492): Create session in memory
-        return;
+        int userId = UserHandle.getCallingUserId();
+        int savedCredentialType;
+        final long token = Binder.clearCallingIdentity();
+        try {
+            savedCredentialType = lockSettingService.getCredentialType(userId);
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+        int keyguardCredentailsType = lockPatternUtilsToKeyguardType(savedCredentialType);
+        LockscreenVerificationSession session =
+                mRemoteLockscreenValidationSessionStorage.startSession(userId);
+        PublicKey publicKey = session.getKeyPair().getPublic();
+        byte[] encodedPublicKey = SecureBox.encodePublicKey(publicKey);
+        int badGuesses = mDatabase.getBadRemoteGuessCounter(userId);
+        return new StartLockscreenValidationRequest.Builder()
+                .setLockscreenUiType(keyguardCredentailsType)
+                .setSourcePublicKey(new byte[]{})
+                .build();
     }
 
     /**
      * Verifies encrypted credentials guess from a remote device.
      */
-    public void validateRemoteLockscreen(@NonNull byte[] encryptedCredential) {
+    public RemoteLockscreenValidationResult validateRemoteLockscreen(
+            @NonNull byte[] encryptedCredential,
+            LockSettingsService lockSettingService) {
+        if (mRemoteLockscreenValidationSessionStorage == null) {
+            throw new UnsupportedOperationException("Under development");
+        }
         checkVerifyRemoteLockscreenPermission();
-        // TODO(b/254335492): Decrypt and verify credentials
-        return;
+        int userId = UserHandle.getCallingUserId();
+        LockscreenVerificationSession session =
+                mRemoteLockscreenValidationSessionStorage.get(userId);
+        if (session == null) {
+            throw new IllegalStateException("There is no active lock screen check session");
+        }
+        // TODO(b/254335492): Call lockSettingService.verifyCredential
+        return new RemoteLockscreenValidationResult.Builder().build();
     }
 
     private void checkVerifyRemoteLockscreenPermission() {
@@ -995,6 +1051,21 @@
         mCleanupManager.registerRecoveryAgent(userId, uid);
     }
 
+    private int lockPatternUtilsToKeyguardType(int credentialsType) {
+        switch(credentialsType) {
+            case LockPatternUtils.CREDENTIAL_TYPE_NONE:
+                throw new IllegalStateException("Screen lock is not set");
+            case LockPatternUtils.CREDENTIAL_TYPE_PATTERN:
+                return KeyguardManager.PATTERN;
+            case LockPatternUtils.CREDENTIAL_TYPE_PIN:
+                return KeyguardManager.PIN;
+            case LockPatternUtils.CREDENTIAL_TYPE_PASSWORD:
+                return KeyguardManager.PASSWORD;
+            default:
+                throw new IllegalStateException("Screen lock is not set");
+        }
+    }
+
     private void checkRecoverKeyStorePermission() {
         mContext.enforceCallingOrSelfPermission(
                 Manifest.permission.RECOVER_KEYSTORE,
diff --git a/services/tests/servicestests/src/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManagerTest.java b/services/tests/servicestests/src/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManagerTest.java
index bb79fd8..b9adc30 100644
--- a/services/tests/servicestests/src/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManagerTest.java
+++ b/services/tests/servicestests/src/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManagerTest.java
@@ -40,6 +40,7 @@
 import android.Manifest;
 import android.app.KeyguardManager;
 import android.app.PendingIntent;
+import android.app.StartLockscreenValidationRequest;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Binder;
@@ -61,11 +62,13 @@
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.widget.LockPatternUtils;
 import com.android.security.SecureBox;
+import com.android.server.locksettings.LockSettingsService;
 import com.android.server.locksettings.recoverablekeystore.storage.ApplicationKeyStorage;
 import com.android.server.locksettings.recoverablekeystore.storage.CleanupManager;
 import com.android.server.locksettings.recoverablekeystore.storage.RecoverableKeyStoreDb;
 import com.android.server.locksettings.recoverablekeystore.storage.RecoverySessionStorage;
 import com.android.server.locksettings.recoverablekeystore.storage.RecoverySnapshotStorage;
+import com.android.server.locksettings.recoverablekeystore.storage.RemoteLockscreenValidationSessionStorage;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -160,14 +163,17 @@
     @Mock private ApplicationKeyStorage mApplicationKeyStorage;
     @Mock private CleanupManager mCleanupManager;
     @Mock private ScheduledExecutorService mExecutorService;
+    @Mock private LockSettingsService mLockSettingsService;
     @Spy private TestOnlyInsecureCertificateHelper mTestOnlyInsecureCertificateHelper;
 
+    private int mUserId;
     private RecoverableKeyStoreDb mRecoverableKeyStoreDb;
     private File mDatabaseFile;
     private RecoverableKeyStoreManager mRecoverableKeyStoreManager;
     private RecoverySessionStorage mRecoverySessionStorage;
     private RecoverySnapshotStorage mRecoverySnapshotStorage;
     private PlatformEncryptionKey mPlatformEncryptionKey;
+    private RemoteLockscreenValidationSessionStorage mRemoteLockscreenValidationSessionStorage;
 
     @Before
     public void setUp() throws Exception {
@@ -177,7 +183,9 @@
         mDatabaseFile = context.getDatabasePath(DATABASE_FILE_NAME);
         mRecoverableKeyStoreDb = RecoverableKeyStoreDb.newInstance(context);
 
+        mUserId = UserHandle.getCallingUserId();
         mRecoverySessionStorage = new RecoverySessionStorage();
+        mRemoteLockscreenValidationSessionStorage = new RemoteLockscreenValidationSessionStorage();
 
         when(mMockContext.getSystemService(anyString())).thenReturn(mKeyguardManager);
         when(mMockContext.getSystemServiceName(any())).thenReturn("test");
@@ -198,7 +206,8 @@
                 mPlatformKeyManager,
                 mApplicationKeyStorage,
                 mTestOnlyInsecureCertificateHelper,
-                mCleanupManager);
+                mCleanupManager,
+                mRemoteLockscreenValidationSessionStorage);
     }
 
     @After
@@ -1269,6 +1278,85 @@
         verify(mExecutorService).schedule(any(Runnable.class), anyLong(), any());
     }
 
+    @Test
+    public void startRemoteLockscreenValidation_credentialsNotSet() throws Exception {
+        when(mLockSettingsService.getCredentialType(anyInt())).thenReturn(
+                LockPatternUtils.CREDENTIAL_TYPE_NONE);
+        try {
+            mRecoverableKeyStoreManager.startRemoteLockscreenValidation(mLockSettingsService);
+            fail("should have thrown");
+        } catch (IllegalStateException e) {
+            assertThat(e.getMessage()).contains("not set");
+        }
+        verify(mLockSettingsService).getCredentialType(mUserId);
+        mRemoteLockscreenValidationSessionStorage.finishSession(mUserId);
+    }
+
+    @Test
+    public void startRemoteLockscreenValidation_checksPermission() throws Exception {
+        when(mLockSettingsService.getCredentialType(anyInt())).thenReturn(
+                LockPatternUtils.CREDENTIAL_TYPE_PIN);
+        mRecoverableKeyStoreManager.startRemoteLockscreenValidation(mLockSettingsService);
+        // TODO(b/254335492): Check new system permission
+        verify(mMockContext, times(1))
+                .enforceCallingOrSelfPermission(
+                        eq(Manifest.permission.RECOVER_KEYSTORE), any());
+        mRemoteLockscreenValidationSessionStorage.finishSession(mUserId);
+    }
+
+    @Test
+    public void startRemoteLockscreenValidation_returnsCredentailsType() throws Exception {
+        when(mLockSettingsService.getCredentialType(anyInt())).thenReturn(
+                LockPatternUtils.CREDENTIAL_TYPE_PIN);
+        StartLockscreenValidationRequest request =
+                mRecoverableKeyStoreManager.startRemoteLockscreenValidation(mLockSettingsService);
+        int credetialsType = request.getLockscreenUiType();
+
+        assertThat(credetialsType).isEqualTo(KeyguardManager.PIN);
+
+        verify(mLockSettingsService).getCredentialType(anyInt());
+        mRemoteLockscreenValidationSessionStorage.finishSession(mUserId);
+    }
+
+    @Test
+    public void startRemoteLockscreenValidation_returnsRemainingAttempts() throws Exception {
+        when(mLockSettingsService.getCredentialType(anyInt())).thenReturn(
+                LockPatternUtils.CREDENTIAL_TYPE_PATTERN);
+        mRecoverableKeyStoreDb.setBadRemoteGuessCounter(mUserId, 3);
+        StartLockscreenValidationRequest request =
+                mRecoverableKeyStoreManager.startRemoteLockscreenValidation(mLockSettingsService);
+        int credetialsType = request.getLockscreenUiType();
+        assertThat(credetialsType).isEqualTo(KeyguardManager.PATTERN);
+        // TODO(b/254335492): Verify returned value
+        mRemoteLockscreenValidationSessionStorage.finishSession(mUserId);
+    }
+
+    @Test
+    public void startRemoteLockscreenValidation_password() throws Exception {
+        when(mLockSettingsService.getCredentialType(anyInt())).thenReturn(
+                LockPatternUtils.CREDENTIAL_TYPE_PASSWORD);
+        mRecoverableKeyStoreDb.setBadRemoteGuessCounter(mUserId, 3);
+        StartLockscreenValidationRequest request =
+                mRecoverableKeyStoreManager.startRemoteLockscreenValidation(mLockSettingsService);
+        int credetialsType = request.getLockscreenUiType();
+        assertThat(credetialsType).isEqualTo(KeyguardManager.PASSWORD);
+        mRemoteLockscreenValidationSessionStorage.finishSession(mUserId);
+    }
+
+    @Test
+    public void validateRemoteLockscreen_noActiveSession() throws Exception {
+        when(mLockSettingsService.getCredentialType(anyInt())).thenReturn(
+                LockPatternUtils.CREDENTIAL_TYPE_NONE);
+        byte[] invalidGuess = new byte[]{1, 2, 3};
+        try {
+            mRecoverableKeyStoreManager.validateRemoteLockscreen(invalidGuess,
+                    mLockSettingsService);
+            fail("should have thrown");
+        } catch (IllegalStateException e) {
+            assertThat(e.getMessage()).contains("session");
+        }
+    }
+
     private static byte[] encryptedApplicationKey(
             SecretKey recoveryKey, byte[] applicationKey) throws Exception {
         return KeySyncUtils.encryptKeysWithRecoveryKey(recoveryKey, ImmutableMap.of(