AES 128 bit & AES 256 bit encryption decryption

Question

I am doing AES 128 bit encyption and decryption using following java code which works fine. For same key and data it gives me same output each time.

link1: http://aesencryption.net/#Java-aes-encryption-example

(final String strPssword = "dAtAbAsE98765432";)

For AES 256 bit encryption and decryption I found another java code. It gives me different output each time.

link2: AES-256 Password Based Encryption/Decryption in Java

My question is that, whether i need to wirte different code for AES 128 bit and AES 256 bit? Or are they same? only key size is different?

For 256 bit encryption only i need to change in first java code link

public boolean setKey(String sKey){
    arbtKey = Arrays.copyOf(arbtKey, 32); // use only first 256 bits
}

public static void main(String[] aryCmdArgs)
{
    final String sKey = "dAtAbAsE98765432dAtAbAsE98765432"; //256 bits
}

or i need to use a code given in link2?

score 1 · Accepted Answer · answered Apr 26 '17 at 10:54

The sample code for the 256-bit key encryption uses a random salt, which is why output will be different from one execution to the next. As for using the code from the first (128-bit) sample, you just supply a key with a supported length. You just supply the algorithm name ("AES") and it will figure the rest out from the key length. Supported lengths are 128, 192 and 256 bits.

AES 128 bit & AES 256 bit encryption decryption

1 Answers1