Java實(shí)現(xiàn)的對(duì)稱加密算法3DES定義與用法示例

更新時(shí)間：2018年04月02日 12:06:37 作者：chengqiuming

這篇文章主要介紹了Java實(shí)現(xiàn)的對(duì)稱加密算法3DES定義與用法,結(jié)合實(shí)例形式簡(jiǎn)單分析了Java 3DES加密算法的相關(guān)定義與使用技巧,需要的朋友可以參考下

本文實(shí)例講述了Java實(shí)現(xiàn)的對(duì)稱加密算法3DES定義與用法。分享給大家供大家參考，具體如下：

一為什么出現(xiàn)3DES

1、返回柯克霍夫原則
2、存在安全問題

二 3DES（Triple DES或DESede）好處

1、密鑰長(zhǎng)度增強(qiáng)
2、迭代次數(shù)提高

三 3DES相關(guān)參數(shù)

四 3DES代碼實(shí)現(xiàn)

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());//默認(rèn)長(zhǎng)度
   SecretKey secretKey = keyGenerator.generateKey();
   byte[] bytesKey = secretKey.getEncoded();
   //KEY轉(zhuǎn)換
   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();
  }
 }
}

五實(shí)現(xiàn)效果