自己写的一个可逆的C#加密算法

using System;
using System.Collections.Generic;
using System.Text;

namespace CLFWeb.Community
{
/********************************************************************************************************
     * 公共类（加解密）
     * Copyright (C) 2008-2009 By 石家庄云天信息技术有限公司
     * songjh20080616(创建标识)

     * 修改标识
     * 修改描述

     * 修改标识
     * 修改描述
    *********************************************************************************************************/

 

   public  class PassWord
    {
       private PassWord()
       { }
       /// <summary>
       /// 解密程序
       /// </summary>
       /// <param name="dd">加密的密码</param>
       /// <returns>解密后的密码</returns>
       public static string JieMi(string dd)
       {
           string vkey = "zhangzengbao";
           int vkeylen = vkey.Length;
           int vKeyPos = 0;
           int vSrcPos = 0;
           int vSrcAsc = 0;
           int vTmpSrcAsc = 0;
           string vDest = "";
           string ff = dd.Substring(0, 2);
           int ddddd = Convert.ToInt32(ff, 16);
           string fff = Convert.ToString(ddddd, 10);
           int vOffset = Convert.ToInt32(fff);

           vSrcPos = 2;
           while (vSrcPos < dd.Length)
           {
             
               int eee = Convert.ToInt32(dd.Substring(vSrcPos, 2), 16);

               vSrcAsc = Convert.ToInt32(Convert.ToString(eee, 10));
               if (vKeyPos < vkeylen)
               {
                   vKeyPos = vKeyPos + 1;
               }
               else
               {
                   vKeyPos = 1;
               }
               char ddddff = (vkey[vKeyPos - 1]);
               //vKeyPos = vKeyPos - 1;
               vTmpSrcAsc = vSrcAsc ^ (int)(vkey[vKeyPos - 1]);
               if (vTmpSrcAsc <= vOffset)
               {
                   vTmpSrcAsc = 255 + vTmpSrcAsc - vOffset;
               }
               else
               {
                   vTmpSrcAsc = vTmpSrcAsc - vOffset;
               }

               vDest = vDest + (char)(vTmpSrcAsc);
               vOffset = vSrcAsc;
              vSrcPos = vSrcPos + 2;
           }
           return vDest;
       }
       /// <summary>
       /// 加密程序
       /// </summary>
       /// <param name="dd">要加密的字符串</param>
       /// <returns>加密后的字符串</returns>
       public static string JiaMi(string dd)
       {
        
           string vkey = "zhangzengbao";
           int vkeylen = vkey.Length;
           int vKeyPos = 0;
           int vSrcAsc = 0;
           int vRange = 256;
           int voffset = 0;
           string vDest = "";
           Random ro = new Random();
           voffset = ro.Next(vRange);
           //voffset = ro.Next(17, 256);
      
           vDest = Convert.ToString(voffset, 16);
           if (vDest.Length < 2)
           {
               vDest = "0" + vDest;
           }
           for (int i = 0; i < dd.Length; i++)
           {
               //byte[] B = Encoding.ASCII.GetBytes(a);
             //  byte[] b = Encoding.ASCII.GetBytes(dd[i].ToString());
             //  int bb =(int) b[0];
               vSrcAsc = ((int)dd[i] + voffset) % 255;//求模
              // vSrcAsc = (bb + voffset) % 255;
               if (vKeyPos<vkeylen)
               {
                   vKeyPos = vKeyPos + 1;
               }
               else
               {
                   vKeyPos = 1;
               }

               vRange = (int)(vkey[vKeyPos-1]);
               //byte[] c = Encoding.ASCII.GetBytes(vkey[vKeyPos - 1].ToString());
              // int cc = (int)c[0];
               //vRange = cc;
               vSrcAsc=vSrcAsc ^ vRange;
               string v1=Convert.ToString(vSrcAsc, 16);
               if (v1.Length < 2)
               {
                   v1 = "0" + v1;
               }
               vDest = vDest +v1;
   
               voffset=vSrcAsc;
   
           }
           vDest = vDest.ToUpper();
           return vDest;

       }
   }
}