Use the AES Encryption Algorithm in Java

AES is a Federation standard for private keys or symmetric encryption. Advanced Encryption Standard in cryptography
Encryption Standard, AES), also known as Rijndael Encryption algorithm. It supports a combination of keys and block sizes of 128,192 and 256.

 

Java Implementation of AES

Import javax. crypto. cipher; <br/> import javax. crypto. keyGenerator; <br/> import javax. crypto. secretKey; <br/> import javax. crypto. spec. secretKeySpec; <br/> public class AES {<br/>/** <br/> * convert a byte array to a hexadecimal string <br/> *@ param buf is converted to a hex byte array <br/> * @ return: The generated hexadecimal String <br/> */<br/> public static String asHex (byte buf []) {<br/> // buf. length * 2 byte array to hexadecimal format, multiply by 2 <br/> StringBuffer strbuf = new StringBuffer (buf. length * 2); <br/> int I; <br/> for (I = 0; I <buf. length; I ++) {<br/> if (int) buf [I] & 0xff) <0x10) <br/> strbuf. append ("0"); // If buf [I] & 0xff is less than 10, add 0 <br/> strbuf. append (Long. toString (int) buf [I] & 0xff, 16); <br/>}< br/> return strbuf. toString (); <br/>}< br/> public static void main (String [] args) throws Exception {<br/> String message = "This is just an example"; <br/> // obtain the key generator <br/> KeyGenerator kgen = KeyGenerator. getInstance ("AES"); <br/> kgen. init (128); // 192 and 256 bits may be unavailable <br/> // generate a key secret protocol <br/> SecretKey skey = kgen. generateKey (); <br/> byte [] raw = skey. getEncoded (); // encode the key into a byte array <br/> SecretKeySpec skeySpec = new SecretKeySpec (raw, "AES "); <br/> // initialize the password object <br/> Cipher cipher = Cipher. getInstance ("AES"); <br/> cipher. init (Cipher. ENCRYPT_MODE, skeySpec); // sets the password object to the encryption mode and sets the encryption key secret protocol <br/> // encrypts the string byte array through the password object, generate an encrypted byte array <br/> byte [] encrypted = cipher. doFinal (message. getBytes (); <br/> System. out. println ("encrypted string:" + asHex (encrypted); <br/> cipher. init (Cipher. DECRYPT_MODE, skeySpec); // set the password object to the decryption mode and set the decryption key secret protocol <br/> byte [] original = cipher. doFinal (encrypted); // decrypt the byte array by using the password object to generate a decryption byte array <br/> String originalString = new String (original ); // restore the original string <br/> System. out. println ("Original string:" + originalString + "" <br/> + asHex (original); <br/>}< br/> 

This is just a simple AES implementation that demonstrates how to use strong cryptographic technology for development. Other elastic and robust encryption technologies can be used in Java. You can visit the internet.

 

Link: http://java.sun.com/developer/technicalArticles/Security/AES/AES_v1.html

 

AES encryption algorithm home page: http://www.nist.gov/aes

 

Encryption Algorithm Introduction: http://news.csdn.net/n/20070425/103328.html