java实现DES加密四步走

用java实现DES加密主要有四步：

import java.security.Key;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class DESImpl {

	public static void main(String[] args) throws Exception {

		String string = "Hello World!";
		byte[] bytes = string.getBytes();

		// Step 1: Provider support
		Security.addProvider(new com.sun.crypto.provider.SunJCE());

		// Step 2: Get algorithm instance
		Cipher cipher = Cipher.getInstance("DES");

		// Step 3: Initial
		byte[] keyBytes = "64BitKEY".getBytes();
		Key key = new SecretKeySpec(keyBytes, "DES");
		cipher.init(Cipher.ENCRYPT_MODE, key);

		// Step 4: Do final
		byte[] result = cipher.doFinal(bytes);

	}
}

 

其中密钥KEY为64bit