Java实现的对称加密算法3DES定义与用法示例

2019-11-26 10:07:15

字体：大中小

来源：转载

供稿：网友

本文实例讲述了Java实现的对称加密算法3DES定义与用法。分享给大家供大家参考，具体如下：

一为什么出现3DES

1、返回柯克霍夫原则
2、存在安全问题

二 3DES（Triple DES或DESede）好处

1、密钥长度增强
2、迭代次数提高

三 3DES相关参数

四 3DES代码实现

package com.imooc.security.des;import java.security.Key;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESedeKeySpec;import org.apache.commons.codec.binary.Base64;public class Imooc3DES { private static String src = "cakin24 security 3des"; public static void main(String[] args) {  jdk3DES(); } public static void jdk3DES() {  try {   //生成KEY   KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");   //keyGenerator.init(168);   keyGenerator.init(new SecureRandom());//默认长度   SecretKey secretKey = keyGenerator.generateKey();   byte[] bytesKey = secretKey.getEncoded();   //KEY转换   DESedeKeySpec desedeKeySpec = new DESedeKeySpec(bytesKey);   SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");   Key convertSecretKey = factory.generateSecret(desedeKeySpec);   //加密   Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");   cipher.init(Cipher.ENCRYPT_MODE, convertSecretKey);   byte[] result = cipher.doFinal(src.getBytes());   System.out.println("jdk 3des encrypt : " + Base64.encodeBase64String(result));   //解密   cipher.init(Cipher.DECRYPT_MODE, convertSecretKey);   result = cipher.doFinal(result);   System.out.println("jdk 3des decrypt : " + new String(result));  } catch (Exception e) {   e.printStackTrace();  } }}

五实现效果