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

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 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

jdk 3des encrypt : 6t7a/rnardzsl+mtezvbfxwnnzr0yjbw
jdk 3des decrypt : cakin24 security 3des

注：这里引入了org.apache.commons.codec.binary.base64包，可点击此处本站下载。

希望本文所述对大家java程序设计有所帮助。

原文链接：https://blog.csdn.net/chengqiuming/article/details/78746057