一个私钥加密的例子

using System;
using System.Security;
using System.Security.Cryptography;
using System.IO;

namespace cry
{
    /**//// <summary>
    /// Cryop 的摘要说明。
    /// </summary>
    public class Cryop
    {
        //Keys与IV的长度相等
        private static Byte[] Keys = System.Text.Encoding.Unicode.GetBytes("天天向上");
        private static Byte[] IV = new Byte[]{0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
        

        /**//// <summary>
        /// 加密
        /// </summary>
        public static Byte[] Enc(String test)
        {            
            System.Security.Cryptography.RC2CryptoServiceProvider rc2 = new RC2CryptoServiceProvider();
            MemoryStream msStream = new MemoryStream();    
            byte[] toEncrypt;    
            try
            {
                ICryptoTransform encrypt = rc2.CreateEncryptor(Keys,IV);
                
                CryptoStream csStream = new CryptoStream(msStream,encrypt,CryptoStreamMode.Write);

                toEncrypt = System.Text.Encoding.Unicode.GetBytes(test);
                csStream.Write(toEncrypt,0,toEncrypt.Length);
                csStream.FlushFinalBlock();
            }
            catch(Exception ex)
            {
                throw new Exception(ex.Message,ex);
            }
            return msStream.ToArray();

        } 

        /**//// <summary>
        /// 解密
        /// </summary>
        public static String Dec(Byte[] enc)
        {
            System.Security.Cryptography.RC2CryptoServiceProvider rc2 = new RC2CryptoServiceProvider();
            try
            {
                ICryptoTransform decrypt = rc2.CreateDecryptor(Keys,IV);
                MemoryStream msDec = new MemoryStream(enc);
                CryptoStream csDec = new CryptoStream(msDec,decrypt,CryptoStreamMode.Read);
                byte[] fromEncpty = new Byte[enc.Length];
                csDec.Read(fromEncpty,0,fromEncpty.Length);
                return System.Text.Encoding.Unicode.GetString(fromEncpty);
            }
            catch(Exception ex)
            {
                throw new Exception(ex.Message,ex);
            }
            
        }
    }
}