diff --git a/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKey.java b/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKey.java
index f4faaf43..3d086aec 100644
--- a/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKey.java
+++ b/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKey.java
@@ -16,10 +16,12 @@ import org.jetbrains.annotations.NotNull;
 public abstract class MasterKey {
 
     @SuppressWarnings("UnusedDeclaration")
-    private static final Logger logger = Logger.get( MasterKey.class );
+    private static final Logger  logger               = Logger.get( MasterKey.class );
+    private static       boolean allowNativeByDefault = true;
 
     @Nonnull
     private final String fullName;
+    private boolean allowNative = allowNativeByDefault;
 
     @Nullable
     private byte[] masterKey;
@@ -46,6 +48,23 @@ public abstract class MasterKey {
         throw new UnsupportedOperationException( "Unsupported version: " + version );
     }
 
+    public static boolean isAllowNativeByDefault() {
+        return allowNativeByDefault;
+    }
+
+    /**
+     * Native libraries are useful for speeding up the performance of cryptographical functions.
+     * Sometimes, however, we may prefer to use Java-only code.
+     * For instance, for auditability / trust or because the native code doesn't work on our CPU/platform.
+     * <p/>
+     * This setter affects the default setting for any newly created {@link MasterKey}s.
+     *
+     * @param allowNative false to disallow the use of native libraries.
+     */
+    public static void setAllowNativeByDefault(final boolean allowNative) {
+        allowNativeByDefault = allowNative;
+    }
+
     protected MasterKey(@NotNull final String fullName) {
 
         this.fullName = fullName;
@@ -63,6 +82,15 @@ public abstract class MasterKey {
         return fullName;
     }
 
+    public boolean isAllowNative() {
+        return allowNative;
+    }
+
+    public MasterKey setAllowNative(final boolean allowNative) {
+        this.allowNative = allowNative;
+        return this;
+    }
+
     @Nonnull
     protected byte[] getKey() {
 
diff --git a/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV0.java b/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV0.java
index 4ece61c3..b84872ab 100644
--- a/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV0.java
+++ b/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV0.java
@@ -65,8 +65,15 @@ public class MasterKeyV0 extends MasterKey {
         mpBytesBuf.get( mpBytes, 0, mpBytes.length );
         Arrays.fill( mpBytesBuf.array(), (byte) 0 );
 
+        return scrypt( masterKeySalt, mpBytes );
+    }
+
+    protected byte[] scrypt(final byte[] masterKeySalt, final byte[] mpBytes) {
         try {
-            return SCrypt.scrypt( mpBytes, masterKeySalt, MP_N, MP_r, MP_p, MP_dkLen );
+            if (isAllowNative())
+                return SCrypt.scrypt( mpBytes, masterKeySalt, MP_N, MP_r, MP_p, MP_dkLen );
+            else
+                return SCrypt.scryptJ( mpBytes, masterKeySalt, MP_N, MP_r, MP_p, MP_dkLen );
         }
         catch (GeneralSecurityException e) {
             logger.bug( e );
diff --git a/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV3.java b/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV3.java
index db8d87d5..bc620a5d 100644
--- a/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV3.java
+++ b/MasterPassword/Java/masterpassword-algorithm/src/main/java/com/lyndir/masterpassword/MasterKeyV3.java
@@ -14,7 +14,7 @@ import javax.annotation.Nullable;
 /**
  * bugs:
  * - no known issues.
- * 
+ *
  * @author lhunath, 2014-08-30
  */
 public class MasterKeyV3 extends MasterKeyV2 {
@@ -46,17 +46,8 @@ public class MasterKeyV3 extends MasterKeyV2 {
         ByteBuffer mpBytesBuf = MP_charset.encode( CharBuffer.wrap( masterPassword ) );
         byte[] mpBytes = new byte[mpBytesBuf.remaining()];
         mpBytesBuf.get( mpBytes, 0, mpBytes.length );
-        Arrays.fill( mpBytesBuf.array(), (byte)0 );
+        Arrays.fill( mpBytesBuf.array(), (byte) 0 );
 
-        try {
-            return SCrypt.scrypt( mpBytes, masterKeySalt, MP_N, MP_r, MP_p, MP_dkLen );
-        }
-        catch (GeneralSecurityException e) {
-            logger.bug( e );
-            return null;
-        }
-        finally {
-            Arrays.fill( mpBytes, (byte) 0 );
-        }
+        return scrypt( masterKeySalt, mpBytes );
     }
 }
diff --git a/MasterPassword/Java/masterpassword-android/AndroidManifest.xml b/MasterPassword/Java/masterpassword-android/AndroidManifest.xml
index 2f9c1f5f..a3947036 100644
--- a/MasterPassword/Java/masterpassword-android/AndroidManifest.xml
+++ b/MasterPassword/Java/masterpassword-android/AndroidManifest.xml
@@ -12,13 +12,13 @@
             android:icon="@drawable/icon"
             android:label="@string/app_name"
             android:allowBackup="true">
-        <activity android:name=".TestActivity" android:theme="@style/MPTheme">
+        <activity android:name=".EmergencyActivity" android:theme="@style/MPTheme">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".EmergencyActivity" android:theme="@style/MPTheme" />
+        <activity android:name=".TestActivity" android:theme="@style/MPTheme" />
     </application>
     
 </manifest>
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_gears.png b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_gears.png
new file mode 100644
index 00000000..c939369e
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_gears.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_key.png b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_key.png
new file mode 100644
index 00000000..25ea04cf
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_key.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_plus.png b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_plus.png
new file mode 100644
index 00000000..53fec014
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/icon_plus.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/identity.png b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/identity.png
new file mode 100644
index 00000000..b166f8f9
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/identity.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_identity.png b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_identity.png
new file mode 100644
index 00000000..74b24312
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_identity.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_key.png b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_key.png
new file mode 100644
index 00000000..3156342d
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_key.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_stats.png b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_stats.png
new file mode 100644
index 00000000..13be8b1d
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-mdpi/img_stats.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_gears.png b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_gears.png
new file mode 100644
index 00000000..e4cbaf04
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_gears.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_key.png b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_key.png
new file mode 100644
index 00000000..af6c44cd
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_key.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_plus.png b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_plus.png
new file mode 100644
index 00000000..cffdd7d9
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/icon_plus.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_identity.png b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_identity.png
new file mode 100644
index 00000000..1455cdb9
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_identity.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_key.png b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_key.png
new file mode 100644
index 00000000..336ddd36
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_key.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_stats.png b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_stats.png
new file mode 100644
index 00000000..61bfa3f3
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable-xhdpi/img_stats.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/drawable/divider.png b/MasterPassword/Java/masterpassword-android/res/drawable/divider.png
new file mode 100644
index 00000000..35cf2a23
Binary files /dev/null and b/MasterPassword/Java/masterpassword-android/res/drawable/divider.png differ
diff --git a/MasterPassword/Java/masterpassword-android/res/layout/activity_emergency.xml b/MasterPassword/Java/masterpassword-android/res/layout/activity_emergency.xml
index 2d8c6d95..4d578ce4 100644
--- a/MasterPassword/Java/masterpassword-android/res/layout/activity_emergency.xml
+++ b/MasterPassword/Java/masterpassword-android/res/layout/activity_emergency.xml
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+            xmlns:tools="http://schemas.android.com/tools"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:fillViewport="true"
@@ -17,6 +18,13 @@
                 android:layout_height="0dp"
                 android:layout_weight="1" />
 
+        <ImageView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="8dp"
+                android:importantForAccessibility="no"
+                android:src="@drawable/img_identity" />
+
         <EditText
                 android:id="@+id/fullNameField"
                 android:layout_width="match_parent"
@@ -26,14 +34,14 @@
                 android:hint="@string/fullName_hint"
                 android:gravity="center"
                 android:textColor="#FFFFFF"
-                android:textSize="26sp" />
+                android:textSize="16sp" />
 
         <CheckBox
                 android:id="@+id/rememberFullNameField"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:nextFocusForward="@+id/rememberPasswordField"
-                android:textSize="14sp"
+                android:textSize="12sp"
                 android:textColor="@android:color/tertiary_text_dark"
                 android:text="@string/remember" />
 
@@ -46,16 +54,24 @@
                 android:hint="@string/masterPassword_hint"
                 android:gravity="center"
                 android:textColor="#FFFFFF"
-                android:textSize="18sp" />
+                android:textSize="16sp" />
 
         <CheckBox
                 android:id="@id/rememberPasswordField"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:textSize="14sp"
+                android:textSize="12sp"
                 android:textColor="@android:color/tertiary_text_dark"
                 android:text="@string/forgetOnClose" />
 
+        <ImageView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="20dp"
+                android:layout_marginBottom="8dp"
+                android:importantForAccessibility="no"
+                android:src="@drawable/img_key" />
+
         <EditText
                 android:id="@id/siteNameField"
                 android:layout_width="match_parent"
@@ -65,7 +81,7 @@
                 android:hint="@string/siteName_hint"
                 android:gravity="center"
                 android:textColor="#FFFFFF"
-                android:textSize="18sp" />
+                android:textSize="16sp" />
 
         <FrameLayout
                 android:layout_width="match_parent"
@@ -76,7 +92,6 @@
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
                     android:layout_gravity="center"
-                    android:layout_margin="20dp"
                     android:indeterminate="true" />
 
             <LinearLayout
@@ -94,7 +109,7 @@
                         android:background="@android:color/transparent"
                         android:textColor="#FFFFFF"
                         android:textSize="32sp"
-                        android:text="LuxdZozvDuma4["
+                        tools:text="LuxdZozvDuma4["
                         android:onClick="copySitePassword" />
 
                 <TextView
@@ -104,7 +119,7 @@
                         android:labelFor="@id/sitePasswordField"
                         android:gravity="center"
                         android:background="@android:color/transparent"
-                        android:textSize="14sp"
+                        android:textSize="12sp"
                         android:textColor="@android:color/tertiary_text_dark"
                         android:text="@string/sitePassword_hint" />
 
@@ -115,54 +130,136 @@
                 android:id="@+id/maskPasswordField"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:textSize="14sp"
+                android:textSize="12sp"
                 android:textColor="@android:color/tertiary_text_dark"
                 android:text="@string/maskPassword" />
 
-        <Spinner
-                android:id="@id/siteTypeField"
+        <ImageView
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:nextFocusForward="@+id/counterField"
-                android:gravity="center" />
+                android:layout_marginTop="20dp"
+                android:layout_marginBottom="8dp"
+                android:importantForAccessibility="no"
+                android:src="@drawable/divider" />
 
-        <EditText
-                android:id="@id/counterField"
+        <LinearLayout
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:nextFocusForward="@+id/siteVersionField"
-                android:gravity="center"
-                android:inputType="text|textNoSuggestions"
-                android:textColor="#FFFFFF"
-                android:textSize="18sp"
-                android:text="1" />
+                style="?android:buttonBarStyle"
+                android:orientation="horizontal"
+                android:gravity="center">
 
-        <TextView
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:labelFor="@id/counterField"
-                android:gravity="center"
-                android:background="@android:color/transparent"
-                android:textSize="14sp"
-                android:textColor="@android:color/tertiary_text_dark"
-                android:text="@string/siteCounter_hint" />
+            <LinearLayout
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:orientation="vertical"
+                    android:gravity="center">
 
-        <Spinner
-                android:id="@id/siteVersionField"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:nextFocusForward="@id/rememberFullNameField"
-                android:gravity="center" />
+                <Button
+                        android:id="@id/siteTypeField"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:layout_marginStart="8dp"
+                        android:layout_marginEnd="8dp"
+                        style="?android:buttonBarButtonStyle"
+                        android:nextFocusForward="@+id/counterField"
+                        android:gravity="center"
+                        android:textColor="#FFFFFF"
+                        android:textSize="16sp"
+                        android:drawableStart="@drawable/icon_key"
+                        android:drawablePadding="8dp"
+                        android:background="@android:color/transparent"
+                        tools:text="Long" />
 
-        <TextView
+                <TextView
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:labelFor="@id/siteTypeField"
+                        android:gravity="center"
+                        android:background="@android:color/transparent"
+                        android:textSize="12sp"
+                        android:textColor="@android:color/tertiary_text_dark"
+                        android:text="@string/siteType_hint" />
+
+            </LinearLayout>
+
+            <LinearLayout
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:orientation="vertical"
+                    android:gravity="center">
+
+                <Button
+                        android:id="@id/counterField"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:layout_marginStart="8dp"
+                        android:layout_marginEnd="8dp"
+                        style="?android:buttonBarButtonStyle"
+                        android:nextFocusForward="@+id/siteVersionField"
+                        android:gravity="center"
+                        android:textColor="#FFFFFF"
+                        android:textSize="16sp"
+                        android:drawableStart="@drawable/icon_plus"
+                        android:drawablePadding="8dp"
+                        android:background="@android:color/transparent"
+                        tools:text="1" />
+
+                <TextView
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:labelFor="@id/siteVersionField"
+                        android:gravity="center"
+                        android:background="@android:color/transparent"
+                        android:textSize="12sp"
+                        android:textColor="@android:color/tertiary_text_dark"
+                        android:text="@string/siteCounter_hint" />
+
+            </LinearLayout>
+
+            <LinearLayout
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:orientation="vertical"
+                    android:gravity="center">
+
+                <Button
+                        android:id="@id/siteVersionField"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:layout_marginStart="8dp"
+                        android:layout_marginEnd="8dp"
+                        style="?android:buttonBarButtonStyle"
+                        android:nextFocusForward="@+id/rememberFullNameField"
+                        android:gravity="center"
+                        android:textColor="#FFFFFF"
+                        android:textSize="16sp"
+                        android:drawableStart="@drawable/icon_gears"
+                        android:drawablePadding="8dp"
+                        android:background="@android:color/transparent"
+                        tools:text="3" />
+
+                <TextView
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:labelFor="@id/siteVersionField"
+                        android:gravity="center"
+                        android:background="@android:color/transparent"
+                        android:textSize="12sp"
+                        android:textColor="@android:color/tertiary_text_dark"
+                        android:text="@string/siteVersion_hint" />
+
+            </LinearLayout>
+        </LinearLayout>
+
+        <Button
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:labelFor="@id/siteVersionField"
-                android:gravity="center"
-                android:background="@android:color/transparent"
-                android:textSize="14sp"
-                android:textColor="@android:color/tertiary_text_dark"
-                android:text="@string/siteVersion_hint" />
+                android:layout_marginTop="8dp"
+                android:textSize="16sp"
+                android:text="@string/btn_tests"
+                android:onClick="integrityTests"
+                android:background="@android:color/transparent" />
 
         <View
                 android:layout_width="1dp"
diff --git a/MasterPassword/Java/masterpassword-android/res/layout/activity_test.xml b/MasterPassword/Java/masterpassword-android/res/layout/activity_test.xml
index 81170812..b3d6fdc6 100644
--- a/MasterPassword/Java/masterpassword-android/res/layout/activity_test.xml
+++ b/MasterPassword/Java/masterpassword-android/res/layout/activity_test.xml
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+            xmlns:tools="http://schemas.android.com/tools"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:fillViewport="true"
@@ -17,22 +18,31 @@
                 android:layout_height="0dp"
                 android:layout_weight="1" />
 
+        <ImageView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:importantForAccessibility="no"
+                android:src="@drawable/img_stats" />
+
         <ProgressBar
                 android:id="@+id/progressView"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:layout_gravity="center"
                 android:layout_margin="8dp"
-                style="@android:style/Widget.ProgressBar.Horizontal" />
+                tools:max="100"
+                tools:progress="80"
+                style="?android:progressBarStyleHorizontal" />
 
         <TextView
                 android:id="@+id/statusView"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
+                android:labelFor="@id/sitePasswordField"
                 android:gravity="center"
                 android:background="@android:color/transparent"
-                android:textSize="14sp"
-                android:textColor="@android:color/secondary_text_dark"
+                android:textSize="12sp"
+                android:textColor="@android:color/tertiary_text_dark"
                 android:text="@string/tests_testing" />
 
         <TextView
@@ -53,8 +63,15 @@
                 android:layout_marginTop="8dp"
                 android:enabled="false"
                 android:text="@string/tests_btn_testing"
-                android:onClick="onAction"/>
+                android:onClick="onAction" />
 
+        <CheckBox
+                android:id="@+id/nativeKDF"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:textSize="12sp"
+                android:textColor="@android:color/tertiary_text_dark"
+                android:text="@string/nativeKDF" />
     </LinearLayout>
 
 </ScrollView>
diff --git a/MasterPassword/Java/masterpassword-android/res/values/strings.xml b/MasterPassword/Java/masterpassword-android/res/values/strings.xml
index e01c7f06..ffd4b787 100644
--- a/MasterPassword/Java/masterpassword-android/res/values/strings.xml
+++ b/MasterPassword/Java/masterpassword-android/res/values/strings.xml
@@ -8,15 +8,18 @@
     <string name="masterPassword_hint">Your master password</string>
     <string name="siteName_hint">eg. google.com</string>
     <string name="sitePassword_hint">Tap to copy</string>
-    <string name="siteCounter_hint">Password #</string>
+    <string name="siteType_hint">Type</string>
+    <string name="siteCounter_hint">Counter</string>
     <string name="siteVersion_hint">Algorithm</string>
     <string name="empty" />
+    <string name="btn_tests">Integrity Tests</string>
     <string name="tests_unavailable">Test suite unavailable.</string>
-    <string name="tests_btn_unavailable">Exit</string>
+    <string name="tests_btn_unavailable">Retest</string>
     <string name="tests_testing">Testing device\'s password generation integrity…</string>
     <string name="tests_btn_testing">Please Stand By…</string>
     <string name="tests_failed">Incompatible device or OS.</string>
-    <string name="tests_btn_failed">Exit</string>
+    <string name="tests_btn_failed">Retest</string>
     <string name="tests_passed">Integrity checks passed!</string>
     <string name="tests_btn_passed">Continue</string>
+    <string name="nativeKDF">Use native key derivation</string>
 </resources>
diff --git a/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/EmergencyActivity.java b/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/EmergencyActivity.java
index cd738aa2..fb25c644 100644
--- a/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/EmergencyActivity.java
+++ b/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/EmergencyActivity.java
@@ -61,13 +61,13 @@ public class EmergencyActivity extends Activity {
     EditText siteNameField;
 
     @InjectView(R.id.siteTypeField)
-    Spinner siteTypeField;
+    Button siteTypeField;
 
     @InjectView(R.id.counterField)
-    EditText counterField;
+    Button counterField;
 
     @InjectView(R.id.siteVersionField)
-    Spinner siteVersionField;
+    Button siteVersionField;
 
     @InjectView(R.id.sitePasswordField)
     Button sitePasswordField;
@@ -104,9 +104,9 @@ public class EmergencyActivity extends Activity {
         fullNameField.setOnFocusChangeListener( updateMasterKey );
         masterPasswordField.setOnFocusChangeListener( updateMasterKey );
         siteNameField.addTextChangedListener( updateSitePassword );
-        siteTypeField.setOnItemSelectedListener( updateSitePassword );
+//        siteTypeField.setOnItemSelectedListener( updateSitePassword );
         counterField.addTextChangedListener( updateSitePassword );
-        siteVersionField.setOnItemSelectedListener( updateMasterKey );
+//        siteVersionField.setOnItemSelectedListener( updateMasterKey );
         sitePasswordField.addTextChangedListener( new ValueChangedListener() {
             @Override
             void update() {
@@ -127,11 +127,11 @@ public class EmergencyActivity extends Activity {
         sitePasswordField.setTypeface( Res.sourceCodePro_Black );
         sitePasswordField.setPaintFlags( sitePasswordField.getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG );
 
-        siteTypeField.setAdapter( new ArrayAdapter<>( this, R.layout.spinner_item, MPSiteType.forClass( MPSiteTypeClass.Generated ) ) );
-        siteTypeField.setSelection( MPSiteType.GeneratedLong.ordinal() );
+//        siteTypeField.setAdapter( new ArrayAdapter<>( this, R.layout.spinner_item, MPSiteType.forClass( MPSiteTypeClass.Generated ) ) );
+//        siteTypeField.setSelection( MPSiteType.GeneratedLong.ordinal() );
 
-        siteVersionField.setAdapter( new ArrayAdapter<>( this, R.layout.spinner_item, MasterKey.Version.values() ) );
-        siteVersionField.setSelection( MasterKey.Version.CURRENT.ordinal() );
+//        siteVersionField.setAdapter( new ArrayAdapter<>( this, R.layout.spinner_item, MasterKey.Version.values() ) );
+//        siteVersionField.setSelection( MasterKey.Version.CURRENT.ordinal() );
 
         rememberFullNameField.setOnCheckedChangeListener( new CompoundButton.OnCheckedChangeListener() {
             @Override
@@ -162,6 +162,8 @@ public class EmergencyActivity extends Activity {
     protected void onResume() {
         super.onResume();
 
+        MasterKey.setAllowNativeByDefault( isNativeKDFEnabled() );
+
         fullNameField.setText( getPreferences( MODE_PRIVATE ).getString( "fullName", "" ) );
         rememberFullNameField.setChecked( isRememberFullNameEnabled() );
         forgetPasswordField.setChecked( isForgetPasswordEnabled() );
@@ -195,6 +197,10 @@ public class EmergencyActivity extends Activity {
         super.onPause();
     }
 
+    private boolean isNativeKDFEnabled() {
+        return getPreferences( MODE_PRIVATE ).getBoolean( "nativeKDF", MasterKey.isAllowNativeByDefault() );
+    }
+
     private boolean isRememberFullNameEnabled() {
         return getPreferences( MODE_PRIVATE ).getBoolean( "rememberFullName", false );
     }
@@ -210,7 +216,7 @@ public class EmergencyActivity extends Activity {
     private synchronized void updateMasterKey() {
         final String fullName = fullNameField.getText().toString();
         final char[] masterPassword = masterPasswordField.getText().toString().toCharArray();
-        final MasterKey.Version version = (MasterKey.Version) siteVersionField.getSelectedItem();
+        final MasterKey.Version version = MasterKey.Version.CURRENT;//( MasterKey.Version) siteVersionField.getSelectedItem();
         try {
             if (fullName.hashCode() == hc_userName && Arrays.hashCode( masterPassword ) == hc_masterPassword &&
                 masterKeyFuture != null && masterKeyFuture.get().getAlgorithmVersion() == version)
@@ -265,8 +271,10 @@ public class EmergencyActivity extends Activity {
 
     private void updateSitePassword() {
         final String siteName = siteNameField.getText().toString();
-        final MPSiteType type = (MPSiteType) siteTypeField.getSelectedItem();
-        final UnsignedInteger counter = UnsignedInteger.valueOf( ifNotNullElse( counterField.getText(), "1" ).toString() );
+        final MPSiteType type = MPSiteType.GeneratedLong;//(MPSiteType) siteTypeField.getSelectedItem();
+        CharSequence counterText = counterField.getText();
+        final UnsignedInteger counter =
+                TextUtils.isEmpty( counterText )? UnsignedInteger.valueOf( 1L ): UnsignedInteger.valueOf( counterText.toString() );
 
         if (masterKeyFuture == null || siteName.isEmpty() || type == null) {
             sitePasswordField.setText( "" );
@@ -313,6 +321,10 @@ public class EmergencyActivity extends Activity {
         } );
     }
 
+    public void integrityTests(View view) {
+        TestActivity.startNoSkip( this );
+    }
+
     public void copySitePassword(View view) {
         final String currentSitePassword = this.sitePassword;
         if (TextUtils.isEmpty( currentSitePassword ))
diff --git a/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/TestActivity.java b/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/TestActivity.java
index 62625fac..52937610 100644
--- a/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/TestActivity.java
+++ b/MasterPassword/Java/masterpassword-android/src/main/java/com/lyndir/masterpassword/TestActivity.java
@@ -3,9 +3,10 @@ package com.lyndir.masterpassword;
 import static com.lyndir.lhunath.opal.system.util.StringUtils.strf;
 
 import android.app.*;
+import android.content.Context;
+import android.content.Intent;
 import android.os.*;
 import android.view.View;
-import android.view.WindowManager;
 import android.widget.*;
 import butterknife.ButterKnife;
 import butterknife.InjectView;
@@ -21,7 +22,8 @@ import javax.annotation.Nullable;
 public class TestActivity extends Activity implements MPTestSuite.Listener {
 
     @SuppressWarnings("UnusedDeclaration")
-    private static final Logger logger = Logger.get( TestActivity.class );
+    private static final Logger logger            = Logger.get( TestActivity.class );
+    private static final String PREF_TESTS_PASSED = "integrityTestsPassed";
 
     private final ListeningExecutorService backgroundExecutor = MoreExecutors.listeningDecorator( Executors.newSingleThreadExecutor() );
     private final ListeningExecutorService mainExecutor       = MoreExecutors.listeningDecorator( new MainThreadExecutor() );
@@ -38,20 +40,34 @@ public class TestActivity extends Activity implements MPTestSuite.Listener {
     @InjectView(R.id.actionButton)
     Button actionButton;
 
+    @InjectView(R.id.nativeKDF)
+    CheckBox nativeKDF;
+
     private MPTestSuite               testSuite;
     private ListenableFuture<Boolean> testFuture;
     private Runnable                  action;
     private ImmutableSet<String>      testNames;
 
+    public static void startNoSkip(Context context) {
+        context.startActivity( new Intent( context, TestActivity.class ) );
+    }
+
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate( savedInstanceState );
         Res.init( getResources() );
 
-        getWindow().setFlags( WindowManager.LayoutParams.FLAG_SECURE, WindowManager.LayoutParams.FLAG_SECURE );
         setContentView( R.layout.activity_test );
         ButterKnife.inject( this );
 
+        nativeKDF.setOnCheckedChangeListener( new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(final CompoundButton buttonView, final boolean isChecked) {
+                getPreferences( MODE_PRIVATE ).edit().putBoolean( "nativeKDF", isChecked ).apply();
+                MasterKey.setAllowNativeByDefault( isNativeKDFEnabled() );
+            }
+        } );
+
         try {
             setStatus( 0, 0, null );
             testSuite = new MPTestSuite();
@@ -76,63 +92,59 @@ public class TestActivity extends Activity implements MPTestSuite.Listener {
         }
     }
 
-    @Override
-    protected void onStart() {
-        super.onStart();
-
-        final Set<String> integrityTestsPassed = getPreferences( MODE_PRIVATE ).getStringSet( "integrityTestsPassed",
-                                                                                              ImmutableSet.<String>of() );
-        if (!FluentIterable.from( testNames ).anyMatch( new Predicate<String>() {
-            @Override
-            public boolean apply(@Nullable final String testName) {
-                return !integrityTestsPassed.contains( testName );
-            }
-        } )) {
-            // None of the tests we need to perform were missing from the tests that have already been passed on this device.
-            finish();
-            EmergencyActivity.start( TestActivity.this );
-        }
-    }
-
     @Override
     protected void onResume() {
         super.onResume();
 
-        if (testFuture == null) {
-            setStatus( R.string.tests_testing, R.string.tests_btn_testing, null );
-            Futures.addCallback( testFuture = backgroundExecutor.submit( testSuite ), new FutureCallback<Boolean>() {
-                @Override
-                public void onSuccess(@Nullable final Boolean result) {
-                    if (result != null && result)
-                        setStatus( R.string.tests_passed, R.string.tests_btn_passed, new Runnable() {
-                            @Override
-                            public void run() {
-                                getPreferences( MODE_PRIVATE ).edit().putStringSet( "integrityTestsPassed", testNames ).apply();
-                                finish();
-                                EmergencyActivity.start( TestActivity.this );
-                            }
-                        } );
-                    else
-                        setStatus( R.string.tests_failed, R.string.tests_btn_failed, new Runnable() {
-                            @Override
-                            public void run() {
-                                finish();
-                            }
-                        } );
-                }
+        nativeKDF.setChecked( isNativeKDFEnabled() );
 
-                @Override
-                public void onFailure(final Throwable t) {
-                    logger.err( t, "While running test suite" );
+        if (testFuture == null)
+            startTestSuite();
+    }
+
+    private boolean isNativeKDFEnabled() {
+        return getPreferences( MODE_PRIVATE ).getBoolean( "nativeKDF", MasterKey.isAllowNativeByDefault() );
+    }
+
+    private void startTestSuite() {
+        if (testFuture != null)
+            testFuture.cancel( true );
+
+        MasterKey.setAllowNativeByDefault( isNativeKDFEnabled() );
+
+        setStatus( R.string.tests_testing, R.string.tests_btn_testing, null );
+        Futures.addCallback( testFuture = backgroundExecutor.submit( testSuite ), new FutureCallback<Boolean>() {
+            @Override
+            public void onSuccess(@Nullable final Boolean result) {
+                if (result != null && result)
+                    setStatus( R.string.tests_passed, R.string.tests_btn_passed, new Runnable() {
+                        @Override
+                        public void run() {
+                            getPreferences( MODE_PRIVATE ).edit().putStringSet( PREF_TESTS_PASSED, testNames ).apply();
+                            finish();
+                            EmergencyActivity.start( TestActivity.this );
+                        }
+                    } );
+                else
                     setStatus( R.string.tests_failed, R.string.tests_btn_failed, new Runnable() {
                         @Override
                         public void run() {
-                            finish();
+                            startTestSuite();
                         }
                     } );
-                }
-            }, mainExecutor );
-        }
+            }
+
+            @Override
+            public void onFailure(final Throwable t) {
+                logger.err( t, "While running test suite" );
+                setStatus( R.string.tests_failed, R.string.tests_btn_failed, new Runnable() {
+                    @Override
+                    public void run() {
+                        finish();
+                    }
+                } );
+            }
+        }, mainExecutor );
     }
 
     public void onAction(View v) {