diff --git a/src/com/android/settings/CryptKeeperConfirm.java b/src/com/android/settings/CryptKeeperConfirm.java
index 2484948..49d027b 100644
--- a/src/com/android/settings/CryptKeeperConfirm.java
+++ b/src/com/android/settings/CryptKeeperConfirm.java
@@ -38,6 +38,7 @@
 import com.android.internal.widget.LockPatternUtils;
 import com.android.settings.core.InstrumentedFragment;
 
+import java.util.Arrays;
 import java.util.Locale;
 
 public class CryptKeeperConfirm extends InstrumentedFragment {
@@ -87,7 +88,12 @@
                     IStorageManager storageManager = IStorageManager.Stub.asInterface(service);
                     try {
                         Bundle args = getIntent().getExtras();
-                        storageManager.encryptStorage(args.getInt("type", -1), args.getString("password"));
+                        // TODO(b/120484642): Update vold to accept a password as a byte array
+                        byte[] passwordBytes = args.getByteArray("password");
+                        String password = passwordBytes != null ? new String(passwordBytes) : null;
+                        Arrays.fill(passwordBytes, (byte) 0);
+                        storageManager.encryptStorage(args.getInt("type", -1),
+                                password);
                     } catch (Exception e) {
                         Log.e("CryptKeeper", "Error while encrypting...", e);
                     }
diff --git a/src/com/android/settings/password/ChooseLockGeneric.java b/src/com/android/settings/password/ChooseLockGeneric.java
index cf62112..4a758be 100644
--- a/src/com/android/settings/password/ChooseLockGeneric.java
+++ b/src/com/android/settings/password/ChooseLockGeneric.java
@@ -76,6 +76,7 @@
 import com.android.settingslib.widget.FooterPreference;
 import com.android.settingslib.widget.FooterPreferenceMixinCompat;
 
+import java.util.Arrays;
 import java.util.List;
 
 public class ChooseLockGeneric extends SettingsActivity {
@@ -151,7 +152,7 @@
         private boolean mPasswordConfirmed = false;
         private boolean mWaitingForConfirmation = false;
         private boolean mForChangeCredRequiredForBoot = false;
-        private String mUserPassword;
+        private byte[] mUserPassword;
         private LockPatternUtils mLockPatternUtils;
         private FingerprintManager mFingerprintManager;
         private FaceManager mFaceManager;
@@ -200,7 +201,7 @@
                 .getBooleanExtra(CONFIRM_CREDENTIALS, true);
             if (getActivity() instanceof ChooseLockGeneric.InternalActivity) {
                 mPasswordConfirmed = !confirmCredentials;
-                mUserPassword = getActivity().getIntent().getStringExtra(
+                mUserPassword = getActivity().getIntent().getByteArrayExtra(
                         ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
             }
 
@@ -224,7 +225,7 @@
                 mPasswordConfirmed = savedInstanceState.getBoolean(PASSWORD_CONFIRMED);
                 mWaitingForConfirmation = savedInstanceState.getBoolean(WAITING_FOR_CONFIRMATION);
                 if (mUserPassword == null) {
-                    mUserPassword = savedInstanceState.getString(
+                    mUserPassword = savedInstanceState.getByteArray(
                             ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
                 }
             }
@@ -383,11 +384,11 @@
             if (requestCode == CONFIRM_EXISTING_REQUEST && resultCode == Activity.RESULT_OK) {
                 mPasswordConfirmed = true;
                 mUserPassword = data != null
-                    ? data.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD)
+                    ? data.getByteArrayExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD)
                     : null;
                 updatePreferencesOrFinish(false /* isRecreatingActivity */);
                 if (mForChangeCredRequiredForBoot) {
-                    if (!TextUtils.isEmpty(mUserPassword)) {
+                    if (!(mUserPassword == null || mUserPassword.length == 0)) {
                         maybeEnableEncryption(
                                 mLockPatternUtils.getKeyguardStoredPasswordQuality(mUserId), false);
                     } else {
@@ -447,7 +448,7 @@
             outState.putBoolean(PASSWORD_CONFIRMED, mPasswordConfirmed);
             outState.putBoolean(WAITING_FOR_CONFIRMATION, mWaitingForConfirmation);
             if (mUserPassword != null) {
-                outState.putString(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD, mUserPassword);
+                outState.putByteArray(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD, mUserPassword);
             }
         }
 
@@ -669,7 +670,7 @@
             setPreferenceSummary(ScreenLockType.MANAGED, R.string.secure_lock_encryption_warning);
         }
 
-        protected Intent getLockManagedPasswordIntent(String password) {
+        protected Intent getLockManagedPasswordIntent(byte[] password) {
             return mManagedPasswordProvider.createIntent(false, password);
         }
 
diff --git a/src/com/android/settings/password/ChooseLockPassword.java b/src/com/android/settings/password/ChooseLockPassword.java
index cd48182..c9d1af3 100644
--- a/src/com/android/settings/password/ChooseLockPassword.java
+++ b/src/com/android/settings/password/ChooseLockPassword.java
@@ -78,6 +78,7 @@
 import com.google.android.setupdesign.GlifLayout;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public class ChooseLockPassword extends SettingsActivity {
@@ -123,7 +124,7 @@
             return this;
         }
 
-        public IntentBuilder setPassword(String password) {
+        public IntentBuilder setPassword(byte[] password) {
             mIntent.putExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD, password);
             return this;
         }
@@ -185,8 +186,8 @@
         private static final String KEY_CURRENT_PASSWORD = "current_password";
         private static final String FRAGMENT_TAG_SAVE_AND_FINISH = "save_and_finish_worker";
 
-        private String mCurrentPassword;
-        private String mChosenPassword;
+        private byte[] mCurrentPassword;
+        private byte[] mChosenPassword;
         private boolean mHasChallenge;
         private long mChallenge;
         private ImeAwareEditText mPasswordEntry;
@@ -215,7 +216,7 @@
         protected boolean mForFingerprint;
         protected boolean mForFace;
 
-        private String mFirstPin;
+        private byte[] mFirstPin;
         private RecyclerView mPasswordRestrictionView;
         protected boolean mIsAlphaMode;
         protected FooterButton mSkipOrClearButton;
@@ -234,7 +235,7 @@
         private static final int MIN_NUMBER_IN_PASSWORD = 4;
         private static final int MIN_NON_LETTER_IN_PASSWORD = 5;
 
-        // Error code returned from {@link #validatePassword(String)}.
+        // Error code returned from {@link #validatePassword(byte[])}.
         static final int NO_ERROR = 0;
         static final int CONTAIN_INVALID_CHARACTERS = 1 << 0;
         static final int TOO_SHORT = 1 << 1;
@@ -394,12 +395,13 @@
                 SaveAndFinishWorker w = new SaveAndFinishWorker();
                 final boolean required = getActivity().getIntent().getBooleanExtra(
                         EncryptionInterstitial.EXTRA_REQUIRE_PASSWORD, true);
-                String current = intent.getStringExtra(
+                byte[] currentBytes = intent.getByteArrayExtra(
                         ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
+
                 w.setBlocking(true);
                 w.setListener(this);
-                w.start(mChooseLockSettingsHelper.utils(), required,
-                        false, 0, current, current, mRequestedQuality, mUserId);
+                w.start(mChooseLockSettingsHelper.utils(), required, false, 0,
+                        currentBytes, currentBytes, mRequestedQuality, mUserId);
             }
             mTextChangedHandler = new TextChangedHandler();
         }
@@ -474,7 +476,8 @@
             Intent intent = getActivity().getIntent();
             final boolean confirmCredentials = intent.getBooleanExtra(
                     ChooseLockGeneric.CONFIRM_CREDENTIALS, true);
-            mCurrentPassword = intent.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
+            mCurrentPassword = intent.getByteArrayExtra(
+                    ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
             mHasChallenge = intent.getBooleanExtra(
                     ChooseLockSettingsHelper.EXTRA_KEY_HAS_CHALLENGE, false);
             mChallenge = intent.getLongExtra(ChooseLockSettingsHelper.EXTRA_KEY_CHALLENGE, 0);
@@ -486,8 +489,9 @@
                             mUserId);
                 }
             } else {
+
                 // restore from previous state
-                mFirstPin = savedInstanceState.getString(KEY_FIRST_PIN);
+                mFirstPin = savedInstanceState.getByteArray(KEY_FIRST_PIN);
                 final String state = savedInstanceState.getString(KEY_UI_STAGE);
                 if (state != null) {
                     mUiStage = Stage.valueOf(state);
@@ -495,7 +499,7 @@
                 }
 
                 if (mCurrentPassword == null) {
-                    mCurrentPassword = savedInstanceState.getString(KEY_CURRENT_PASSWORD);
+                    mCurrentPassword = savedInstanceState.getByteArray(KEY_CURRENT_PASSWORD);
                 }
 
                 // Re-attach to the exiting worker if there is one.
@@ -553,8 +557,8 @@
         public void onSaveInstanceState(Bundle outState) {
             super.onSaveInstanceState(outState);
             outState.putString(KEY_UI_STAGE, mUiStage.name());
-            outState.putString(KEY_FIRST_PIN, mFirstPin);
-            outState.putString(KEY_CURRENT_PASSWORD, mCurrentPassword);
+            outState.putByteArray(KEY_FIRST_PIN, mFirstPin);
+            outState.putByteArray(KEY_CURRENT_PASSWORD, mCurrentPassword);
         }
 
         @Override
@@ -567,7 +571,7 @@
                         getActivity().setResult(RESULT_FINISHED);
                         getActivity().finish();
                     } else {
-                        mCurrentPassword = data.getStringExtra(
+                        mCurrentPassword = data.getByteArrayExtra(
                                 ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
                     }
                     break;
@@ -712,22 +716,22 @@
          * @return the validation result.
          */
         @VisibleForTesting
-        int validatePassword(String password) {
+        int validatePassword(byte[] password) {
             int errorCode = NO_ERROR;
             final PasswordMetrics metrics = PasswordMetrics.computeForPassword(password);
             mergeMinComplexityAndDpmRequirements(metrics.quality);
 
-            if (password.length() < mPasswordMinLength) {
+            if (password == null || password.length < mPasswordMinLength) {
                 if (mPasswordMinLength > mPasswordMinLengthToFulfillAllPolicies) {
                     errorCode |= TOO_SHORT;
                 }
-            } else if (password.length() > mPasswordMaxLength) {
+            } else if (password.length > mPasswordMaxLength) {
                 errorCode |= TOO_LONG;
             } else {
                 // The length requirements are fulfilled.
                 if (!mPasswordNumSequenceAllowed
                         && !requiresLettersOrSymbols()
-                        && metrics.numeric == password.length()) {
+                        && metrics.numeric == password.length) {
                     // Check for repeated characters or sequences (e.g. '1234', '0000', '2468')
                     // if DevicePolicyManager or min password complexity requires a complex numeric
                     // password. There can be two cases in the UI: 1. User chooses to enroll a
@@ -757,8 +761,8 @@
             }
 
             // Allow non-control Latin-1 characters only.
-            for (int i = 0; i < password.length(); i++) {
-                char c = password.charAt(i);
+            for (int i = 0; i < password.length; i++) {
+                char c = (char) password[i];
                 if (c < 32 || c > 127) {
                     errorCode |= CONTAIN_INVALID_CHARACTERS;
                     break;
@@ -809,8 +813,9 @@
 
         public void handleNext() {
             if (mSaveAndFinishWorker != null) return;
-            mChosenPassword = mPasswordEntry.getText().toString();
-            if (TextUtils.isEmpty(mChosenPassword)) {
+            // TODO(b/120484642): This is a point of entry for passwords from the UI
+            mChosenPassword = LockPatternUtils.charSequenceToByteArray(mPasswordEntry.getText());
+            if (mChosenPassword == null || mChosenPassword.length == 0) {
                 return;
             }
             if (mUiStage == Stage.Introduction) {
@@ -818,9 +823,11 @@
                     mFirstPin = mChosenPassword;
                     mPasswordEntry.setText("");
                     updateStage(Stage.NeedToConfirm);
+                } else {
+                    Arrays.fill(mChosenPassword, (byte) 0);
                 }
             } else if (mUiStage == Stage.NeedToConfirm) {
-                if (mFirstPin.equals(mChosenPassword)) {
+                if (Arrays.equals(mFirstPin, mChosenPassword)) {
                     startSaveAndFinish();
                 } else {
                     CharSequence tmp = mPasswordEntry.getText();
@@ -828,6 +835,7 @@
                         Selection.setSelection((Spannable) tmp, 0, tmp.length());
                     }
                     updateStage(Stage.ConfirmWrong);
+                    Arrays.fill(mChosenPassword, (byte) 0);
                 }
             }
         }
@@ -940,8 +948,8 @@
          */
         protected void updateUi() {
             final boolean canInput = mSaveAndFinishWorker == null;
-            String password = mPasswordEntry.getText().toString();
-            final int length = password.length();
+            byte[] password = LockPatternUtils.charSequenceToByteArray(mPasswordEntry.getText());
+            final int length = password.length;
             if (mUiStage == Stage.Introduction) {
                 mPasswordRestrictionView.setVisibility(View.VISIBLE);
                 final int errorCode = validatePassword(password);
@@ -967,6 +975,7 @@
 
             setNextText(mUiStage.buttonText);
             mPasswordEntryInputDisabler.setInputEnabled(canInput);
+            Arrays.fill(password, (byte) 0);
         }
 
         protected int toVisibility(boolean visibleOrGone) {
@@ -1025,6 +1034,18 @@
         public void onChosenLockSaveFinished(boolean wasSecureBefore, Intent resultData) {
             getActivity().setResult(RESULT_FINISHED, resultData);
 
+            if (mChosenPassword != null) {
+                Arrays.fill(mChosenPassword, (byte) 0);
+            }
+            if (mCurrentPassword != null) {
+                Arrays.fill(mCurrentPassword, (byte) 0);
+            }
+            if (mFirstPin != null) {
+                Arrays.fill(mFirstPin, (byte) 0);
+            }
+
+            mPasswordEntry.setText("");
+
             if (!wasSecureBefore) {
                 Intent intent = getRedactionInterstitialIntent(getActivity());
                 if (intent != null) {
@@ -1061,13 +1082,13 @@
 
     public static class SaveAndFinishWorker extends SaveChosenLockWorkerBase {
 
-        private String mChosenPassword;
-        private String mCurrentPassword;
+        private byte[] mChosenPassword;
+        private byte[] mCurrentPassword;
         private int mRequestedQuality;
 
         public void start(LockPatternUtils utils, boolean required,
                 boolean hasChallenge, long challenge,
-                String chosenPassword, String currentPassword, int requestedQuality, int userId) {
+                byte[] chosenPassword, byte[] currentPassword, int requestedQuality, int userId) {
             prepare(utils, required, hasChallenge, challenge, userId);
 
             mChosenPassword = chosenPassword;
diff --git a/src/com/android/settings/password/ChooseLockPattern.java b/src/com/android/settings/password/ChooseLockPattern.java
index 584cc61..d5ad1ab 100644
--- a/src/com/android/settings/password/ChooseLockPattern.java
+++ b/src/com/android/settings/password/ChooseLockPattern.java
@@ -55,6 +55,7 @@
 import com.google.android.setupdesign.GlifLayout;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -114,7 +115,7 @@
             return this;
         }
 
-        public IntentBuilder setPattern(String pattern) {
+        public IntentBuilder setPattern(byte[] pattern) {
             mIntent.putExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD, pattern);
             return this;
         }
@@ -187,7 +188,7 @@
 
         private static final String FRAGMENT_TAG_SAVE_AND_FINISH = "save_and_finish_worker";
 
-        private String mCurrentPattern;
+        private byte[] mCurrentPattern;
         private boolean mHasChallenge;
         private long mChallenge;
         protected TextView mTitleText;
@@ -224,7 +225,7 @@
                         getActivity().setResult(RESULT_FINISHED);
                         getActivity().finish();
                     } else {
-                        mCurrentPattern = data.getStringExtra(
+                        mCurrentPattern = data.getByteArrayExtra(
                                 ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
                     }
 
@@ -457,12 +458,12 @@
                 SaveAndFinishWorker w = new SaveAndFinishWorker();
                 final boolean required = getActivity().getIntent().getBooleanExtra(
                         EncryptionInterstitial.EXTRA_REQUIRE_PASSWORD, true);
-                String current = intent.getStringExtra(
+                byte[] current = intent.getByteArrayExtra(
                         ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
                 w.setBlocking(true);
                 w.setListener(this);
                 w.start(mChooseLockSettingsHelper.utils(), required,
-                        false, 0, LockPatternUtils.stringToPattern(current), current, mUserId);
+                        false, 0, LockPatternUtils.byteArrayToPattern(current), current, mUserId);
             }
             mForFingerprint = intent.getBooleanExtra(
                     ChooseLockSettingsHelper.EXTRA_KEY_FOR_FINGERPRINT, false);
@@ -540,7 +541,8 @@
             final boolean confirmCredentials = getActivity().getIntent()
                     .getBooleanExtra(ChooseLockGeneric.CONFIRM_CREDENTIALS, true);
             Intent intent = getActivity().getIntent();
-            mCurrentPattern = intent.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
+            mCurrentPattern =
+                    intent.getByteArrayExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
             mHasChallenge = intent.getBooleanExtra(
                     ChooseLockSettingsHelper.EXTRA_KEY_HAS_CHALLENGE, false);
             mChallenge = intent.getLongExtra(ChooseLockSettingsHelper.EXTRA_KEY_CHALLENGE, 0);
@@ -563,13 +565,13 @@
                 }
             } else {
                 // restore from previous state
-                final String patternString = savedInstanceState.getString(KEY_PATTERN_CHOICE);
-                if (patternString != null) {
-                    mChosenPattern = LockPatternUtils.stringToPattern(patternString);
+                final byte[] pattern = savedInstanceState.getByteArray(KEY_PATTERN_CHOICE);
+                if (pattern != null) {
+                    mChosenPattern = LockPatternUtils.byteArrayToPattern(pattern);
                 }
 
                 if (mCurrentPattern == null) {
-                    mCurrentPattern = savedInstanceState.getString(KEY_CURRENT_PATTERN);
+                    mCurrentPattern = savedInstanceState.getByteArray(KEY_CURRENT_PATTERN);
                 }
                 updateStage(Stage.values()[savedInstanceState.getInt(KEY_UI_STAGE)]);
 
@@ -665,13 +667,12 @@
 
             outState.putInt(KEY_UI_STAGE, mUiStage.ordinal());
             if (mChosenPattern != null) {
-                outState.putString(KEY_PATTERN_CHOICE,
-                        LockPatternUtils.patternToString(mChosenPattern));
+                outState.putByteArray(KEY_PATTERN_CHOICE,
+                        LockPatternUtils.patternToByteArray(mChosenPattern));
             }
 
             if (mCurrentPattern != null) {
-                outState.putString(KEY_CURRENT_PATTERN,
-                        mCurrentPattern);
+                outState.putByteArray(KEY_CURRENT_PATTERN, mCurrentPattern);
             }
         }
 
@@ -818,6 +819,10 @@
         public void onChosenLockSaveFinished(boolean wasSecureBefore, Intent resultData) {
             getActivity().setResult(RESULT_FINISHED, resultData);
 
+            if (mCurrentPattern != null) {
+                Arrays.fill(mCurrentPattern, (byte) 0);
+            }
+
             if (!wasSecureBefore) {
                 Intent intent = getRedactionInterstitialIntent(getActivity());
                 if (intent != null) {
@@ -831,12 +836,12 @@
     public static class SaveAndFinishWorker extends SaveChosenLockWorkerBase {
 
         private List<LockPatternView.Cell> mChosenPattern;
-        private String mCurrentPattern;
+        private byte[] mCurrentPattern;
         private boolean mLockVirgin;
 
         public void start(LockPatternUtils utils, boolean credentialRequired,
                 boolean hasChallenge, long challenge,
-                List<LockPatternView.Cell> chosenPattern, String currentPattern, int userId) {
+                List<LockPatternView.Cell> chosenPattern, byte[] currentPattern, int userId) {
             prepare(utils, credentialRequired, hasChallenge, challenge, userId);
 
             mCurrentPattern = currentPattern;
diff --git a/src/com/android/settings/password/ConfirmLockPassword.java b/src/com/android/settings/password/ConfirmLockPassword.java
index f893870..6c61967 100644
--- a/src/com/android/settings/password/ConfirmLockPassword.java
+++ b/src/com/android/settings/password/ConfirmLockPassword.java
@@ -323,8 +323,9 @@
                 return;
             }
 
-            final String pin = mPasswordEntry.getText().toString();
-            if (TextUtils.isEmpty(pin)) {
+            // TODO(b/120484642): This is a point of entry for passwords from the UI
+            final byte[] pin = LockPatternUtils.charSequenceToByteArray(mPasswordEntry.getText());
+            if (pin == null || pin.length == 0) {
                 return;
             }
 
@@ -350,7 +351,7 @@
             return getActivity() instanceof ConfirmLockPassword.InternalActivity;
         }
 
-        private void startVerifyPassword(final String pin, final Intent intent) {
+        private void startVerifyPassword(final byte[] pin, final Intent intent) {
             long challenge = getActivity().getIntent().getLongExtra(
                     ChooseLockSettingsHelper.EXTRA_KEY_CHALLENGE, 0);
             final int localEffectiveUserId = mEffectiveUserId;
@@ -381,7 +382,7 @@
                             onVerifyCallback);
         }
 
-        private void startCheckPassword(final String pin, final Intent intent) {
+        private void startCheckPassword(final byte[] pin, final Intent intent) {
             final int localEffectiveUserId = mEffectiveUserId;
             mPendingLockCheck = LockPatternChecker.checkPassword(
                     mLockPatternUtils,
diff --git a/src/com/android/settings/password/ConfirmLockPattern.java b/src/com/android/settings/password/ConfirmLockPattern.java
index 29cdfef..6d3d6e5 100644
--- a/src/com/android/settings/password/ConfirmLockPattern.java
+++ b/src/com/android/settings/password/ConfirmLockPattern.java
@@ -448,7 +448,7 @@
                                 mLockPatternUtils, pattern, challenge, localUserId,
                                 onVerifyCallback)
                         : LockPatternChecker.verifyTiedProfileChallenge(
-                                mLockPatternUtils, LockPatternUtils.patternToString(pattern),
+                                mLockPatternUtils, LockPatternUtils.patternToByteArray(pattern),
                                 true, challenge, localUserId, onVerifyCallback);
             }
 
@@ -473,7 +473,7 @@
                                     intent.putExtra(ChooseLockSettingsHelper.EXTRA_KEY_TYPE,
                                                     StorageManager.CRYPT_TYPE_PATTERN);
                                     intent.putExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD,
-                                                    LockPatternUtils.patternToString(pattern));
+                                                    LockPatternUtils.patternToByteArray(pattern));
                                 }
                                 mCredentialCheckResultTracker.setResult(matched, intent, timeoutMs,
                                         localEffectiveUserId);
diff --git a/src/com/android/settings/password/ManagedLockPasswordProvider.java b/src/com/android/settings/password/ManagedLockPasswordProvider.java
index 2494af5..5006926 100644
--- a/src/com/android/settings/password/ManagedLockPasswordProvider.java
+++ b/src/com/android/settings/password/ManagedLockPasswordProvider.java
@@ -59,7 +59,7 @@
      * @param password Current lock password.
      * @return Intent that should update lock password to a managed password.
      */
-    Intent createIntent(boolean requirePasswordToDecrypt, String password) {
+    Intent createIntent(boolean requirePasswordToDecrypt, byte[] password) {
         return null;
     }
 }
diff --git a/src/com/android/settings/security/CryptKeeperSettings.java b/src/com/android/settings/security/CryptKeeperSettings.java
index c80ad11..6555f56 100644
--- a/src/com/android/settings/security/CryptKeeperSettings.java
+++ b/src/com/android/settings/security/CryptKeeperSettings.java
@@ -173,7 +173,7 @@
 
         if (helper.utils().getKeyguardStoredPasswordQuality(UserHandle.myUserId())
                 == DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED) {
-            showFinalConfirmation(StorageManager.CRYPT_TYPE_DEFAULT, "");
+            showFinalConfirmation(StorageManager.CRYPT_TYPE_DEFAULT, "".getBytes());
             return true;
         }
 
@@ -193,14 +193,14 @@
         // confirmation prompt; otherwise, go back to the initial state.
         if (resultCode == Activity.RESULT_OK && data != null) {
             int type = data.getIntExtra(ChooseLockSettingsHelper.EXTRA_KEY_TYPE, -1);
-            String password = data.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
-            if (!TextUtils.isEmpty(password)) {
+            byte[] password = data.getByteArrayExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
+            if (!(password == null || password.length == 0)) {
                 showFinalConfirmation(type, password);
             }
         }
     }
 
-    private void showFinalConfirmation(int type, String password) {
+    private void showFinalConfirmation(int type, byte[] password) {
         Preference preference = new Preference(getPreferenceManager().getContext());
         preference.setFragment(CryptKeeperConfirm.class.getName());
         preference.setTitle(R.string.crypt_keeper_confirm_title);
@@ -208,16 +208,16 @@
         ((SettingsActivity) getActivity()).onPreferenceStartFragment(null, preference);
     }
 
-    private void addEncryptionInfoToPreference(Preference preference, int type, String password) {
+    private void addEncryptionInfoToPreference(Preference preference, int type, byte[] password) {
         Activity activity = getActivity();
         DevicePolicyManager dpm = (DevicePolicyManager)
                 activity.getSystemService(Context.DEVICE_POLICY_SERVICE);
         if (dpm.getDoNotAskCredentialsOnBoot()) {
             preference.getExtras().putInt(TYPE, StorageManager.CRYPT_TYPE_DEFAULT);
-            preference.getExtras().putString(PASSWORD, "");
+            preference.getExtras().putByteArray(PASSWORD, "".getBytes());
         } else {
             preference.getExtras().putInt(TYPE, type);
-            preference.getExtras().putString(PASSWORD, password);
+            preference.getExtras().putByteArray(PASSWORD, password);
         }
     }
 }
diff --git a/src/com/android/settings/security/LockUnificationPreferenceController.java b/src/com/android/settings/security/LockUnificationPreferenceController.java
index 978986c..bf374de 100644
--- a/src/com/android/settings/security/LockUnificationPreferenceController.java
+++ b/src/com/android/settings/security/LockUnificationPreferenceController.java
@@ -70,8 +70,8 @@
     private RestrictedSwitchPreference mUnifyProfile;
 
 
-    private String mCurrentDevicePassword;
-    private String mCurrentProfilePassword;
+    private byte[] mCurrentDevicePassword;
+    private byte[] mCurrentProfilePassword;
     private boolean mKeepDeviceLock;
 
     @Override
@@ -151,13 +151,13 @@
         } else if (requestCode == UNIFY_LOCK_CONFIRM_DEVICE_REQUEST
                 && resultCode == Activity.RESULT_OK) {
             mCurrentDevicePassword =
-                    data.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
+                    data.getByteArrayExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
             launchConfirmProfileLock();
             return true;
         } else if (requestCode == UNIFY_LOCK_CONFIRM_PROFILE_REQUEST
                 && resultCode == Activity.RESULT_OK) {
             mCurrentProfilePassword =
-                    data.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
+                    data.getByteArrayExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
             unifyLocks();
             return true;
         }
@@ -226,7 +226,7 @@
         // PASSWORD_QUALITY_SOMETHING means pattern, everything above means PIN/password.
         if (profileQuality == DevicePolicyManager.PASSWORD_QUALITY_SOMETHING) {
             mLockPatternUtils.saveLockPattern(
-                    LockPatternUtils.stringToPattern(mCurrentProfilePassword),
+                    LockPatternUtils.byteArrayToPattern(mCurrentProfilePassword),
                     mCurrentDevicePassword, MY_USER_ID);
         } else {
             mLockPatternUtils.saveLockPassword(
diff --git a/tests/robotests/src/com/android/settings/password/ChooseLockPasswordTest.java b/tests/robotests/src/com/android/settings/password/ChooseLockPasswordTest.java
index 404d205..73707a6 100644
--- a/tests/robotests/src/com/android/settings/password/ChooseLockPasswordTest.java
+++ b/tests/robotests/src/com/android/settings/password/ChooseLockPasswordTest.java
@@ -87,7 +87,7 @@
     @Test
     public void intentBuilder_setPassword_shouldAddExtras() {
         Intent intent = new IntentBuilder(application)
-                .setPassword("password")
+                .setPassword("password".getBytes())
                 .setPasswordQuality(DevicePolicyManager.PASSWORD_QUALITY_NUMERIC)
                 .setUserId(123)
                 .build();
@@ -95,9 +95,9 @@
         assertThat(intent.getBooleanExtra(ChooseLockSettingsHelper.EXTRA_KEY_HAS_CHALLENGE, true))
                 .named("EXTRA_KEY_HAS_CHALLENGE")
                 .isFalse();
-        assertThat(intent.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD))
+        assertThat(intent.getByteArrayExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD))
                 .named("EXTRA_KEY_PASSWORD")
-                .isEqualTo("password");
+                .isEqualTo("password".getBytes());
         assertThat(intent.getIntExtra(PASSWORD_TYPE_KEY, 0))
                 .named("PASSWORD_TYPE_KEY")
                 .isEqualTo(DevicePolicyManager.PASSWORD_QUALITY_NUMERIC);
@@ -366,7 +366,9 @@
         intent.putExtra(EXTRA_KEY_REQUESTED_MIN_COMPLEXITY, minComplexity);
         ChooseLockPassword activity = buildChooseLockPasswordActivity(intent);
         ChooseLockPasswordFragment fragment = getChooseLockPasswordFragment(activity);
-        int validateResult = fragment.validatePassword(userEnteredPassword);
+        byte[] userEnteredPasswordBytes = userEnteredPassword != null
+                ? userEnteredPassword.getBytes() : null;
+        int validateResult = fragment.validatePassword(userEnteredPasswordBytes);
         String[] messages = fragment.convertErrorCodeToMessages(validateResult);
 
         assertThat(messages).asList().containsExactly((Object[]) expectedValidationResult);
diff --git a/tests/robotests/src/com/android/settings/password/ChooseLockPatternTest.java b/tests/robotests/src/com/android/settings/password/ChooseLockPatternTest.java
index 6b1029c..3509d75 100644
--- a/tests/robotests/src/com/android/settings/password/ChooseLockPatternTest.java
+++ b/tests/robotests/src/com/android/settings/password/ChooseLockPatternTest.java
@@ -52,7 +52,7 @@
     @Test
     public void intentBuilder_setPattern_shouldAddExtras() {
         Intent intent = new IntentBuilder(application)
-                .setPattern("pattern")
+                .setPattern("pattern".getBytes())
                 .setUserId(123)
                 .build();
 
@@ -61,9 +61,9 @@
                 .named("EXTRA_KEY_HAS_CHALLENGE")
                 .isFalse();
         assertThat(intent
-                .getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD))
+                .getByteArrayExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD))
                 .named("EXTRA_KEY_PASSWORD")
-                .isEqualTo("pattern");
+                .isEqualTo("pattern".getBytes());
         assertThat(intent.getIntExtra(Intent.EXTRA_USER_ID, 0))
                 .named("EXTRA_USER_ID")
                 .isEqualTo(123);
diff --git a/tests/robotests/src/com/android/settings/testutils/shadow/ShadowLockPatternUtils.java b/tests/robotests/src/com/android/settings/testutils/shadow/ShadowLockPatternUtils.java
index f287085..e9be346 100644
--- a/tests/robotests/src/com/android/settings/testutils/shadow/ShadowLockPatternUtils.java
+++ b/tests/robotests/src/com/android/settings/testutils/shadow/ShadowLockPatternUtils.java
@@ -66,12 +66,12 @@
     }
 
     @Implementation
-    protected byte[] getPasswordHistoryHashFactor(String currentPassword, int userId) {
+    protected byte[] getPasswordHistoryHashFactor(byte[] currentPassword, int userId) {
         return null;
     }
 
     @Implementation
-    protected boolean checkPasswordHistory(String passwordToCheck, byte[] hashFactor, int userId) {
+    protected boolean checkPasswordHistory(byte[] passwordToCheck, byte[] hashFactor, int userId) {
         return false;
     }
 }