Java Encryption AES 256 Code

By G.S. Jackson

Encryption provides one of the best methods for securing digital data. Encryption allows the user to obfuscate data through a code that can only be decrypted by the user or other trusted individuals. Not surprisingly, programming languages such as Java that are used for managing network traffic and network interfaces have built-in libraries to support data encryption. Many encryption standards exist in the Java libraries, including the AES 256 standard.

AES Encryption

The Advanced Encryption Standard was established in 2002 by the National Institute of Standards and Technology as the standard for data encryption. AES encryption uses the Rijndael encryption algorithm, which involves substitution and permutation methods to create encrypted data from a message. AES standards are widely used for encryption by business and governments. Implementation can be complex for those not familiar with cryptography, but many programming languages, including Java, include libraries that make encryption technology readily available to users.

256-bit Encryption

When encrypting messages, a "key" is generated. In most public encryption schemes, public and private keys work together to ensure that users can share encrypted data. AES 256 is a symmetrical key algorithm, meaning that the same key encrypts and decrypts the message. The key in question will be represented in 256 bits, meaning that someone attempting to break into the message would have to figure out the 256-bit key value. The technology to decipher a 256-bit key in a reasonable amount of time has not yet been invented.

AES 256 Java Libraries

The Java Encryption API encrypts messages and creates keys for the programmer through an interface with encryption class methods. Programmers create a message to encrypt, import the proper encryption libraries, and then use the methods in those libraries to specify an encryption method, generate keys and encrypt the message. The encryption libraries also contain ways to decode encrypted messages using the same encryption key.

Examples

A simple Java coding example displays how to use encryption libraries with the AES 256 specification. The following shows how to create encryption, key and cipher objects in Java to encrypt a message:import java.security.*;import javax.crypto.*;import javax.crypto.spec.*;import java.io.*;class Encrypt{public static void main(String[] args) throws Exception {String message="Message to Decode";KeyGenerator key = KeyGenerator.getInstance("AES");key.init(256); SecretKey s = key.generateKey();byte[] raw = s.getEncoded();SecretKeySpec sskey= new SecretKeySpec(raw, "AES");Cipher c = Cipher.getInstance("AES");cipher.init(Cipher.ENCRYPT_MODE, skey);byte[] encrypted =c.doFinal(message.getBytes());System.out.println("encrypted string: " + asHex(encrypted));}}