diff --git a/app/src/main/java/org/shadowice/flocke/andotp/Activities/MainIntroActivity.java b/app/src/main/java/org/shadowice/flocke/andotp/Activities/MainIntroActivity.java
index d45abf60..6c82517f 100644
--- a/app/src/main/java/org/shadowice/flocke/andotp/Activities/MainIntroActivity.java
+++ b/app/src/main/java/org/shadowice/flocke/andotp/Activities/MainIntroActivity.java
@@ -1,15 +1,22 @@
 package org.shadowice.flocke.andotp.Activities;
 
+import android.app.KeyguardManager;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.design.widget.TextInputEditText;
+import android.text.Editable;
+import android.text.TextWatcher;
 import android.util.SparseArray;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
+import android.widget.EditText;
+import android.widget.LinearLayout;
 import android.widget.Spinner;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import com.heinrichreimersoftware.materialintro.app.IntroActivity;
 import com.heinrichreimersoftware.materialintro.app.SlideFragment;
@@ -91,6 +98,14 @@ public class MainIntroActivity extends IntroActivity {
             encryptionChangedCallback = cb;
         }
 
+        private void generateSelectionMapping() {
+            String[] encValues = getResources().getStringArray(R.array.settings_values_encryption);
+
+            selectionMapping = new SparseArray<>();
+            for (int i = 0; i < encValues.length; i++)
+                selectionMapping.put(i, Constants.EncryptionType.valueOf(encValues[i].toUpperCase()));
+        }
+
         @Override
         public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                                  Bundle savedInstanceState) {
@@ -99,11 +114,7 @@ public class MainIntroActivity extends IntroActivity {
             selection = root.findViewById(R.id.introEncryptionSelection);
             desc = root.findViewById(R.id.introEncryptionDesc);
 
-            String[] encValues = getResources().getStringArray(R.array.settings_values_encryption);
-
-            selectionMapping = new SparseArray<>();
-            for (int i = 0; i < encValues.length; i++)
-                selectionMapping.put(i, Constants.EncryptionType.valueOf(encValues[i].toUpperCase()));
+            generateSelectionMapping();
 
             selection.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                 @Override
@@ -137,6 +148,10 @@ public class MainIntroActivity extends IntroActivity {
 
         private TextView desc = null;
         private Spinner selection = null;
+        private TextView authWarnings = null;
+        private LinearLayout credentialsLayout = null;
+        private TextInputEditText passwordInput = null;
+        private EditText passwordConfirm = null;
 
         private SparseArray<Constants.AuthMethod> selectionMapping;
 
@@ -159,6 +174,27 @@ public class MainIntroActivity extends IntroActivity {
             }
         }
 
+        private void generateSelectionMapping() {
+            Constants.AuthMethod[] authValues = Constants.AuthMethod.values();
+
+            selectionMapping = new SparseArray<>();
+            for (int i = 0; i < authValues.length; i++)
+                selectionMapping.put(i, authValues[i]);
+        }
+
+        private void displayWarning(int resId) {
+            displayWarning(getString(resId));
+        }
+
+        private void displayWarning(String warning) {
+            authWarnings.setVisibility(View.VISIBLE);
+            authWarnings.setText(warning);
+        }
+
+        private void hideWarning() {
+            authWarnings.setVisibility(View.GONE);
+        }
+
         @Override
         public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                                  Bundle savedInstanceState) {
@@ -166,14 +202,14 @@ public class MainIntroActivity extends IntroActivity {
 
             desc = root.findViewById(R.id.introAuthDesc);
             selection = root.findViewById(R.id.introAuthSelection);
+            authWarnings = root.findViewById(R.id.introAuthWarnings);
+            credentialsLayout = root.findViewById(R.id.introCredentialsLayout);
+            passwordInput = root.findViewById(R.id.introPasswordEdit);
+            passwordConfirm = root.findViewById(R.id.introPasswordConfirm);
 
-            Constants.AuthMethod[] authValues = Constants.AuthMethod.values();
-            String[] authEntries = getResources().getStringArray(R.array.settings_entries_auth);
-
-            selectionMapping = new SparseArray<>();
-            for (int i = 0; i < authValues.length; i++)
-                selectionMapping.put(i, authValues[i]);
+            generateSelectionMapping();
 
+            final String[] authEntries = getResources().getStringArray(R.array.settings_entries_auth);
             ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(getIntroActivity(), android.R.layout.simple_spinner_item, authEntries) {
                 @Override
                 public boolean isEnabled(int position){
@@ -198,7 +234,74 @@ public class MainIntroActivity extends IntroActivity {
             spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
             selection.setAdapter(spinnerArrayAdapter);
 
+            selection.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+                @Override
+                public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
+                    Constants.AuthMethod authMethod = selectionMapping.get(i);
+
+                    if (authMethod == Constants.AuthMethod.PASSWORD || authMethod == Constants.AuthMethod.PIN) {
+                        credentialsLayout.setVisibility(View.VISIBLE);
+                    } else {
+                        credentialsLayout.setVisibility(View.INVISIBLE);
+                    }
+
+                    updateNavigation();
+                }
+
+                @Override
+                public void onNothingSelected(AdapterView<?> adapterView) {
+                }
+            });
+
+            TextWatcher textWatcher = new TextWatcher() {
+                @Override
+                public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+                    updateNavigation();
+                }
+
+                @Override
+                public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+                }
+
+                @Override
+                public void afterTextChanged(Editable editable) {
+                }
+            };
+
+            passwordInput.addTextChangedListener(textWatcher);
+            passwordConfirm.addTextChangedListener(textWatcher);
+
             return root;
         }
+
+        @Override
+        public boolean canGoForward() {
+            Constants.AuthMethod authMethod = selectionMapping.get(selection.getSelectedItemPosition());
+
+            if (authMethod == Constants.AuthMethod.PIN || authMethod == Constants.AuthMethod.PASSWORD) {
+                String password = passwordInput.getText().toString();
+                String confirm = passwordConfirm.getText().toString();
+
+                return ! password.isEmpty() && ! confirm.isEmpty() && confirm.equals(password);
+            } else if (authMethod == Constants.AuthMethod.DEVICE) {
+                KeyguardManager km = (KeyguardManager) getContext().getSystemService(KEYGUARD_SERVICE);
+
+                if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP) {
+                    displayWarning(R.string.settings_toast_auth_device_pre_lollipop);
+                    return false;
+                } else if (! km.isKeyguardSecure()) {
+                    displayWarning(R.string.settings_toast_auth_device_not_secure);
+                    return false;
+                }
+
+                hideWarning();
+
+                return true;
+            } else {
+                hideWarning();
+
+                return true;
+            }
+        }
     }
 }
diff --git a/app/src/main/res/layout/component_intro_authentication.xml b/app/src/main/res/layout/component_intro_authentication.xml
index dc6cd41e..5f0d65f8 100644
--- a/app/src/main/res/layout/component_intro_authentication.xml
+++ b/app/src/main/res/layout/component_intro_authentication.xml
@@ -1,79 +1,85 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout
+<android.support.v4.widget.NestedScrollView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    android:orientation="vertical"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:layout_gravity="center"
-    android:gravity="center"
-    android:padding="@dimen/activity_margin_large">
-
-    <TextView
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:textAppearance="@style/TextAppearance.AppCompat.Headline"
-        android:textStyle="bold"
-        android:text="@string/settings_title_auth" />
-
-    <TextView
-        android:id="@+id/introAuthDesc"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:layout_marginTop="@dimen/activity_margin"
-        android:text="@string/intro_slide3_desc_keystore"/>
-
-    <Spinner
-        android:id="@+id/introAuthSelection"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:layout_marginTop="@dimen/activity_margin_large"
-        android:layout_marginStart="@dimen/activity_margin"
-        android:layout_marginEnd="@dimen/activity_margin"
-        android:entries="@array/settings_entries_auth" />
+    android:overScrollMode="never">
 
     <LinearLayout
-        android:id="@+id/introCredentialsLayout"
-        android:visibility="invisible"
         android:orientation="vertical"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:layout_marginTop="@dimen/activity_margin_large"
-        android:paddingStart="@dimen/activity_margin"
-        android:paddingEnd="@dimen/activity_margin">
-
-        <android.support.design.widget.TextInputLayout
-            android:id="@+id/introPasswordLayout"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:hint="@string/settings_hint_password"
-            app:passwordToggleEnabled="true" >
-
-            <android.support.design.widget.TextInputEditText
-                android:id="@+id/introPasswordEdit"
-                android:layout_width="match_parent"
-                android:layout_height="match_parent"
-                android:inputType="textPassword" />
-
-        </android.support.design.widget.TextInputLayout>
-
-        <EditText
-            android:id="@+id/introPasswordConfirm"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:hint="@string/settings_hint_password_confirm"
-            android:inputType="textPassword" />
+        android:layout_gravity="center"
+        android:gravity="center"
+        android:padding="@dimen/activity_margin_large">
 
         <TextView
-            android:id="@+id/introPasswordToShortWarning"
             android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:paddingBottom="@dimen/activity_margin"
-            android:paddingTop="@dimen/activity_margin"
+            android:layout_height="wrap_content"
+            android:textAppearance="@style/TextAppearance.AppCompat.Headline"
+            android:textStyle="bold"
+            android:text="@string/settings_title_auth" />
+
+        <TextView
+            android:id="@+id/introAuthDesc"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="@dimen/activity_margin"
+            android:text="@string/intro_slide3_desc_keystore"/>
+
+        <Spinner
+            android:id="@+id/introAuthSelection"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="@dimen/activity_margin_large"
+            android:layout_marginStart="@dimen/activity_margin"
+            android:layout_marginEnd="@dimen/activity_margin"
+            android:entries="@array/settings_entries_auth" />
+
+        <TextView
+            android:id="@+id/introAuthWarnings"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="@dimen/activity_margin"
             android:visibility="gone"
             android:textAlignment="center"
-            android:text="@string/settings_label_short_password" />
+            android:textStyle="bold" />
+
+        <LinearLayout
+            android:id="@+id/introCredentialsLayout"
+            android:visibility="invisible"
+            android:orientation="vertical"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:layout_marginTop="@dimen/activity_margin_large"
+            android:paddingStart="@dimen/activity_margin"
+            android:paddingEnd="@dimen/activity_margin">
+
+            <android.support.design.widget.TextInputLayout
+                android:id="@+id/introPasswordLayout"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:hint="@string/settings_hint_password"
+                app:passwordToggleEnabled="true" >
+
+                <android.support.design.widget.TextInputEditText
+                    android:id="@+id/introPasswordEdit"
+                    android:layout_width="match_parent"
+                    android:layout_height="match_parent"
+                    android:inputType="textPassword" />
+
+            </android.support.design.widget.TextInputLayout>
+
+            <EditText
+                android:id="@+id/introPasswordConfirm"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:hint="@string/settings_hint_password_confirm"
+                android:inputType="textPassword" />
+
+        </LinearLayout>
 
     </LinearLayout>
 
-</LinearLayout>
\ No newline at end of file
+</android.support.v4.widget.NestedScrollView>
\ No newline at end of file