加密字符串是：admin
密文是：21232F297A57A5A743894A0E4A801FC3
但是复制密文在百度中随便搜索MD5解密，然后输入进行就显示解密后内容为：admin
采用DES加密：
因为DES解密是可以根据传入的Key值，然后产生一个密文
比如参考代码：
/** * DescKey.java * 版权所有(C) 2012 * 创建:cuiran 2012-05-21 10:32:16 */package com.wpn.web.util;import java.security.Key;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import sun.misc.BASE64Decoder;import sun.misc.BASE64Encoder;/** * DES 加密 * @author cuiran * @version TODO */public class DescKey {Key key;public DescKey(String str) {setKey(str);// 生成密匙}public DescKey() {setKey("bjwpn");}/** * 根据参数生成KEY */public void setKey(String strKey) {try {KeyGenerator _generator = KeyGenerator.getInstance("DES");_generator.init(new SecureRandom(strKey.getBytes()));this.key = _generator.generateKey();_generator = null;} catch (Exception e) {throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);}}/** * 加密String明文输入,String密文输出 */public String getEncString(String strMing) {byte[] byteMi = null;byte[] byteMing = null;String strMi = "";BASE64Encoder base64en = new BASE64Encoder();try {byteMing = strMing.getBytes("UTF8");byteMi = this.getEncCode(byteMing);strMi = base64en.encode(byteMi);} catch (Exception e) {throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);} finally {base64en = null;byteMing = null;byteMi = null;}return strMi;}/** * 解密 以String密文输入,String明文输出 ** @param strMi * @return */public String getDesString(String strMi) {BASE64Decoder base64De = new BASE64Decoder();byte[] byteMing = null;byte[] byteMi = null;String strMing = "";try {byteMi = base64De.decodeBuffer(strMi);byteMing = this.getDesCode(byteMi);strMing = new String(byteMing, "UTF8");} catch (Exception e) {throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);} finally {base64De = null;byteMing = null;byteMi = null;}return strMing;}/** * 加密以byte[]明文输入,byte[]密文输出 ** @param byteS * @return */private byte[] getEncCode(byte[] byteS) {byte[] byteFina = null;Cipher cipher;try {cipher = Cipher.getInstance("DES");cipher.init(Cipher.ENCRYPT_MODE, key);byteFina = cipher.doFinal(byteS);} catch (Exception e) {throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);} finally {cipher = null;}return byteFina;}/** * 解密以byte[]密文输入,以byte[]明文输出 ** @param byteD * @return */private byte[] getDesCode(byte[] byteD) {Cipher cipher;byte[] byteFina = null;try {cipher = Cipher.getInstance("DES");cipher.init(Cipher.DECRYPT_MODE, key);byteFina = cipher.doFinal(byteD);} catch (Exception e) {throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);} finally {cipher = null;}return byteFina;}public static void main(String args[]) {DescKey des = new DescKey();// 设置密钥des.setKey("bjwpn");String str1 = "admin";// DES加密String str2 = des.getEncString(str1);String deStr = des.getDesString(str2);System.out.println("密文:" + str2);String str = deStr;// DES解密System.out.println("明文:" + str);}}运行结果为：
密文:sDfSpBoP9+M=明文:admin
如果复制密文在网上去解密 是无法解密的。
但是目前那种方式更安全呢，期待大家一起讨论，谢谢。
，下午某时，天气晴，我在某地，想念你。
