You may have heard of advanced encryption standard, or AES for short but may not know the answer to the question “what is AES 256?” Here are four things you need to know about AES:
Advanced Encryption Standard (AES) is a widely-used encryption algorithm that is used to secure sensitive data, such as financial information and passwords. It is a symmetric-key algorithm, which means that the same key is used for both encrypting and decrypting the data.
AES was developed by the National Institute of Standards and Technology (NIST) and is considered to be a very secure encryption method. It uses a fixed block size of 128 bits and a key size of 128, 192, or 256 bits. The longer the key size, the stronger the encryption. For example, AES256 uses a 256-bit key, which is considered to be very secure.
AES is often used in conjunction with other encryption technologies, such as Transport Layer Security (TLS) and Secure Sockets Layer (SSL), to secure data transmission over the internet. It is also used in a variety of other applications, such as disk encryption and secure shell (SSH) connections.
The Advanced Encryption Standard (AES) is the trusted standard algorithm used by the United States government, as well as other organizations. Although extremely efficient in the 128-bit form, AES also uses 192- and 256-bit keys for very demanding encryption purposes.Dec
All symmetric encryption ciphers use the same key for encryption and decryption. Which means in the sense, both the sender and receiver must have the same key. Each encrypts and decrypts have 128 bits data in chunks by using cryptographic keys 128-, 192- or 256- bits.
Plain text which we use to convert are first converted into Cipher and then outputs into Cipher text bits of 128, 192 & 256.
We need to initialize KeyGenerator and SecretKey in order to make our own Key.
KeyGenerator keyGenerator;
SecretKey secretKey;
Prevent a parameter with getInstance method and initialize the KeyGenerator with keysize 256. Add them in the try catch method to prevent crashes.
try {
keyGenerator = KeyGenerator.getInstance("AES");
keyGenerator.init(256);
secretKey = keyGenerator.generateKey();
} catch (Exception e) {
e.printStackTrace();
}
Now I’m using IV(Initialization Vector) in my code. This is an optional part in AES Encryption but a way better to use. Use it with SecureRandom class.
byte[] IV = new byte[16]; SecureRandom random;
Initialize the IV after declaring it globally.
random = new SecureRandom(); random.nextBytes(IV);
public static byte[] encrypt(byte[] plaintext, SecretKey key, byte[] IV) throws Exception {
Cipher cipher = Cipher.getInstance("AES");
SecretKeySpec keySpec = new SecretKeySpec(key.getEncoded(), "AES");
IvParameterSpec ivSpec = new IvParameterSpec(IV);
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
byte[] cipherText = cipher.doFinal(plaintext);
return cipherText;
}
public static String decrypt(byte[] cipherText, SecretKey key, byte[] IV) {
try {
Cipher cipher = Cipher.getInstance("AES");
SecretKeySpec keySpec = new SecretKeySpec(key.getEncoded(), "AES");
IvParameterSpec ivSpec = new IvParameterSpec(IV);
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
byte[] decryptedText = cipher.doFinal(cipherText);
return new String(decryptedText);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
I’ve used an EditText for the user text field to type whatever the string which needs to be encrypted. Two buttons for getting results respectively. One for Encrypting and other for Decrypting. Also used two TextViews for displaying the values(results). One text is used for displaying encrypted value and the other one for decrypted value.
btn1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
encrypt = encrypt(et.getText().toString().getBytes(), secretKey, IV);
String encryptText = new String(encrypt, "UTF-8");
tv1.setText(encryptText);
} catch (Exception e) {
e.printStackTrace();
}
}
});
btn2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
String decrypt = decrypt(encrypt, secretKey, IV);
tv2.setText(decrypt);
} catch (Exception e) {
e.printStackTrace();
}
}
});
After placing these all you can now see the results of how Encrypt and Decrypt are done through AES 256 Encryption.
Remember that IV(Initialization Vector) is an arbitrary number that is only used along with a secret key for data encryption. To generate the IV we use the SecureRandom class.
From the Initialization vector, We create an IvParameterSpec which is always required when creating the cipher during encryption or decryption.
Connect with our team of Amar InfoTech Android Security experts for assistance with implementing AES 256 encryption in your android project. Our team has experience in implementing AES encryption android projects and can provide the necessary support to ensure a successful implementation.
