diff --git a/app/src/main/java/com/example/encryptednotebook/MainActivity.java b/app/src/main/java/com/example/encryptednotebook/MainActivity.java
index 9f07275..27f27d4 100644
--- a/app/src/main/java/com/example/encryptednotebook/MainActivity.java
+++ b/app/src/main/java/com/example/encryptednotebook/MainActivity.java
@@ -18,6 +18,9 @@ import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import java.math.BigInteger;
+import java.security.SecureRandom;
+
 public class MainActivity extends AppCompatActivity {
 
     public static final int SET_PASSWORD_REQUEST = 1;
@@ -30,8 +33,22 @@ public class MainActivity extends AppCompatActivity {
         setSupportActionBar(toolbar);
         TextView hello = findViewById(R.id.hello);
         hello.setText("Wpisz hasło");
+
+        String saltString = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("SALT", null);
+        if (saltString == null) {
+            String randomString = new BigInteger(130, new SecureRandom()).toString(32);
+            byte[] salt = new byte[8];
+            try {
+                System.arraycopy(randomString.getBytes("UTF-8"), 0, salt, 0, 8);
+                PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).edit().putString("SALT", new String(salt)).apply();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+
+
         boolean isPassCreated = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getBoolean("PASSWORD_CREATED", false);
-        if(!isPassCreated){
+        if (!isPassCreated) {
             Intent pickContactIntent = new Intent(this, SetPasswordActivity.class);
             startActivityForResult(pickContactIntent, SET_PASSWORD_REQUEST);
         }
@@ -43,9 +60,11 @@ public class MainActivity extends AppCompatActivity {
                 EditText password = findViewById(R.id.password);
                 String passValue = password.getText().toString();
                 String savedPassValue = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("PASSWORD", null);
-                if(passValue.equals(savedPassValue)) {
+                if (passValue.equals(savedPassValue)) {
                     Snackbar.make(view, "Dobre hasło", Snackbar.LENGTH_LONG)
                             .setAction("Action", null).show();
+                    Intent intent = new Intent(getApplicationContext(), NotebookActivity.class);
+                    startActivity(intent);
                 } else {
                     Snackbar.make(view, "Złe hasło", Snackbar.LENGTH_LONG)
                             .setAction("Action", null).show();
@@ -80,7 +99,7 @@ public class MainActivity extends AppCompatActivity {
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 
         if (requestCode == SET_PASSWORD_REQUEST) {
-            if(resultCode == Activity.RESULT_OK){
+            if (resultCode == Activity.RESULT_OK) {
                 Toast.makeText(getApplicationContext(), "Udało się ustawić hasło", Toast.LENGTH_SHORT).show();
             }
             if (resultCode == Activity.RESULT_CANCELED) {
diff --git a/app/src/main/java/com/example/encryptednotebook/NotebookActivity.java b/app/src/main/java/com/example/encryptednotebook/NotebookActivity.java
index 968626f..6eef5d7 100644
--- a/app/src/main/java/com/example/encryptednotebook/NotebookActivity.java
+++ b/app/src/main/java/com/example/encryptednotebook/NotebookActivity.java
@@ -1,5 +1,6 @@
 package com.example.encryptednotebook;
 
+import android.content.Intent;
 import android.os.Bundle;
 
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
@@ -12,6 +13,22 @@ import android.preference.PreferenceManager;
 import android.view.View;
 import android.widget.EditText;
 
+import java.io.UnsupportedEncodingException;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.InvalidParameterSpecException;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+import javax.crypto.spec.SecretKeySpec;
+
 public class NotebookActivity extends AppCompatActivity {
 
     @Override
@@ -20,19 +37,81 @@ public class NotebookActivity extends AppCompatActivity {
         setContentView(R.layout.activity_notebook);
         Toolbar toolbar = findViewById(R.id.toolbar);
         setSupportActionBar(toolbar);
+        final EditText text = findViewById(R.id.text);
+
+        String savedPassValue = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("PASSWORD", null);
+        if (savedPassValue != null) {
+            try {
+                SecretKey secretKey = generateKey(savedPassValue);
+                String encryptedText = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("TEXT", null);
+                if (encryptedText != null) {
+                    String noteText = decryptMsg(encryptedText.getBytes(), secretKey);
+                    text.setText(noteText);
+                } else {
+                    text.setText("Twoja notatka");
+                }
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+
 
         FloatingActionButton fab = findViewById(R.id.fab);
         fab.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
-                EditText text = findViewById(R.id.text);
                 String textValue = text.getText().toString();
-                PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).edit().putString("TEXT", textValue).apply();
 
-                Snackbar.make(view, "Udało się zapisać", Snackbar.LENGTH_LONG)
-                        .setAction("Action", null).show();
+                String savedPassValue = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("PASSWORD", null);
+                if (savedPassValue != null) {
+                    try {
+                        SecretKey secretKey = generateKey(savedPassValue);
+                        String encryptedText = new String(encryptMsg(textValue, secretKey));
+                        PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).edit().putString("TEXT", encryptedText).apply();
+
+                        Snackbar.make(view, "Udało się zapisać", Snackbar.LENGTH_LONG)
+                                .setAction("Action", null).show();
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
             }
         });
     }
 
+    public SecretKey generateKey(String password)
+            throws NoSuchAlgorithmException, InvalidKeySpecException {
+        //new PBEKeySpec(password, salt, 10, 128)
+        String saltString = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("SALT", null);
+        byte[] saltBytes;
+        try {
+            saltBytes = saltString.getBytes();
+        } catch (NullPointerException e) {
+            e.printStackTrace();
+            saltBytes = "".getBytes();
+        }
+        PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray(), saltBytes, 10, 128);
+        return new SecretKeySpec(SecretKeyFactory.getInstance("PBKDF2WithHmacSHA512").generateSecret(keySpec).getEncoded(), "AES");
+    }
+
+    public byte[] encryptMsg(String message, SecretKey secret)
+            throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidParameterSpecException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
+        /* Encrypt the message. */
+        Cipher cipher = null;
+        cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
+        cipher.init(Cipher.ENCRYPT_MODE, secret);
+        byte[] cipherText = cipher.doFinal(message.getBytes("UTF-8"));
+        return cipherText;
+    }
+
+    public String decryptMsg(byte[] cipherText, SecretKey secret)
+            throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidParameterSpecException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, UnsupportedEncodingException {
+        /* Decrypt the message, given derived encContentValues and initialization vector. */
+        Cipher cipher = null;
+        cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
+        cipher.init(Cipher.DECRYPT_MODE, secret);
+        String decryptString = new String(cipher.doFinal(cipherText), "UTF-8");
+        return decryptString;
+    }
+
 }