diff --git a/app/src/main/java/me/impy/aegis/IntroActivity.java b/app/src/main/java/me/impy/aegis/IntroActivity.java
index 22209a90..075a0d40 100644
--- a/app/src/main/java/me/impy/aegis/IntroActivity.java
+++ b/app/src/main/java/me/impy/aegis/IntroActivity.java
@@ -5,12 +5,7 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
-import android.support.design.widget.FloatingActionButton;
-import android.support.design.widget.Snackbar;
-import android.support.v7.app.AppCompatActivity;
-import android.support.v7.widget.Toolbar;
 import android.view.View;
-import android.widget.Toast;
 
 import agency.tango.materialintroscreen.MaterialIntroActivity;
 import agency.tango.materialintroscreen.MessageButtonBehaviour;
@@ -23,21 +18,21 @@ public class IntroActivity extends MaterialIntroActivity {
         super.onCreate(savedInstanceState);
 
         addSlide(new SlideFragmentBuilder()
-                        .backgroundColor(R.color.colorPrimary)
-                        .buttonsColor(R.color.colorAccent)
-                        .image(R.drawable.intro_shield)
-                        .title("Welcome")
-                        .description("Aegis is a brand new open source(!) authenticator app which generates tokens for your accounts.")
-                        .build());
+                .backgroundColor(R.color.colorPrimary)
+                .buttonsColor(R.color.colorAccent)
+                .image(R.drawable.intro_shield)
+                .title("Welcome")
+                .description("Aegis is a brand new open source(!) authenticator app which generates tokens for your accounts.")
+                .build());
 
         addSlide(new SlideFragmentBuilder()
-                        .backgroundColor(R.color.colorAccent)
-                        .buttonsColor(R.color.colorPrimary)
-                        .neededPermissions(new String[]{Manifest.permission.CAMERA})
-                        .image(R.drawable.intro_scanner)
-                        .title("Permissions")
-                        .description("Aegis needs permission to your camera in order to function properly. This is needed to scan QR codes.")
-                        .build(),
+                .backgroundColor(R.color.colorAccent)
+                .buttonsColor(R.color.colorPrimary)
+                .neededPermissions(new String[]{Manifest.permission.CAMERA})
+                .image(R.drawable.intro_scanner)
+                .title("Permissions")
+                .description("Aegis needs permission to your camera in order to function properly. This is needed to scan QR codes.")
+                .build(),
                 new MessageButtonBehaviour(new View.OnClickListener() {
                     @Override
                     public void onClick(View v) {
@@ -52,5 +47,4 @@ public class IntroActivity extends MaterialIntroActivity {
         SharedPreferences prefs = this.getSharedPreferences("me.impy.aegis", Context.MODE_PRIVATE);
         prefs.edit().putBoolean("passedIntro", true).apply();
     }
-
 }
diff --git a/app/src/main/java/me/impy/aegis/MainActivity.java b/app/src/main/java/me/impy/aegis/MainActivity.java
index 44b7f6b3..c30cd0b2 100644
--- a/app/src/main/java/me/impy/aegis/MainActivity.java
+++ b/app/src/main/java/me/impy/aegis/MainActivity.java
@@ -369,7 +369,7 @@ public class MainActivity extends AppCompatActivity {
         databaseFile = new DatabaseFile();
 
         try {
-            masterKey = new MasterKey(null);
+            masterKey = MasterKey.generate();
         } catch (NoSuchAlgorithmException e) {
             // TODO: tell the user to stop using a weird platform
             throw new UndeclaredThrowableException(e);
diff --git a/app/src/main/java/me/impy/aegis/crypto/CryptoUtils.java b/app/src/main/java/me/impy/aegis/crypto/CryptoUtils.java
index 37d3c4b3..4938bbbe 100644
--- a/app/src/main/java/me/impy/aegis/crypto/CryptoUtils.java
+++ b/app/src/main/java/me/impy/aegis/crypto/CryptoUtils.java
@@ -25,6 +25,7 @@ public class CryptoUtils {
     public static final byte CRYPTO_KEY_SIZE = 32;
     public static final byte CRYPTO_NONCE_SIZE = 12;
     public static final byte CRYPTO_SALT_SIZE = 32;
+    // TODO: decide on a 'secure-enough' iteration count
     public static final short CRYPTO_ITERATION_COUNT = 10000;
     public static final String CRYPTO_CIPHER_RAW = "AES/ECB/NoPadding";
     public static final String CRYPTO_CIPHER_AEAD = "AES/GCM/NoPadding";
diff --git a/app/src/main/java/me/impy/aegis/crypto/MasterKey.java b/app/src/main/java/me/impy/aegis/crypto/MasterKey.java
index 5676a3c7..b3f268c0 100644
--- a/app/src/main/java/me/impy/aegis/crypto/MasterKey.java
+++ b/app/src/main/java/me/impy/aegis/crypto/MasterKey.java
@@ -16,13 +16,22 @@ import me.impy.aegis.crypto.slots.Slot;
 public class MasterKey {
     private SecretKey _key;
 
-    public MasterKey(SecretKey key) throws NoSuchAlgorithmException {
+    public MasterKey(SecretKey key)  {
         if (key == null) {
-            key = CryptoUtils.generateKey();
+            throw new NullPointerException();
         }
         _key = key;
     }
 
+    public static MasterKey generate() throws NoSuchAlgorithmException {
+        return new MasterKey(CryptoUtils.generateKey());
+    }
+
+    public void encryptSlot(Slot slot, Cipher cipher)
+            throws BadPaddingException, IllegalBlockSizeException {
+        slot.setKey(_key, cipher);
+    }
+
     public static MasterKey decryptSlot(Slot slot, Cipher cipher)
             throws BadPaddingException, IllegalBlockSizeException, NoSuchAlgorithmException {
         return new MasterKey(slot.getKey(cipher));
@@ -41,8 +50,4 @@ public class MasterKey {
         Cipher cipher = CryptoUtils.createCipher(_key, Cipher.DECRYPT_MODE, params.Nonce);
         return CryptoUtils.decrypt(bytes, cipher, params);
     }
-
-    public void encryptSlot(Slot slot, Cipher cipher) throws BadPaddingException, IllegalBlockSizeException {
-        slot.setKey(_key, cipher);
-    }
 }
diff --git a/app/src/main/java/me/impy/aegis/crypto/slots/FingerprintSlot.java b/app/src/main/java/me/impy/aegis/crypto/slots/FingerprintSlot.java
index 09157180..6f47a666 100644
--- a/app/src/main/java/me/impy/aegis/crypto/slots/FingerprintSlot.java
+++ b/app/src/main/java/me/impy/aegis/crypto/slots/FingerprintSlot.java
@@ -1,5 +1,8 @@
 package me.impy.aegis.crypto.slots;
 
 public class FingerprintSlot extends RawSlot {
-
+    @Override
+    public byte getType() {
+        return TYPE_FINGERPRINT;
+    }
 }