求加密方法，可以加可以解，谢

Question

我想了解一下加密的方法，最好多些注释

Answer 1

最简单的加密，你可以把要加密的字符串中每个字符都替换为相应的ACS码，需要的时候在替换回来但一定要使用StringBuilder！

Answer 2

1.如果只需要简单得md5加密,这样:
System.Web.Security.FormAuthentication.HashPasswordForStoringInConfigFile("你要加密得字符串","md5");
2.如果比较复杂得加密，这里提供一个Rijndael加密算法得加密demo
using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;namespace RijndaelManaged_Examples
{
    class MyMainClass
    {
        public static void Main()
        {
            string original = "This is a much longer string of data than a public/private key algorithm will accept.";
            string roundtrip;
            ASCIIEncoding textConverter = new ASCIIEncoding();
            RijndaelManaged myRijndael = new RijndaelManaged();
            byte[] fromEncrypt;
            byte[] encrypted;
            byte[] toEncrypt;
            byte[] key;
            byte[] IV;            //Create a new key and initialization vector.
            myRijndael.GenerateKey();
            myRijndael.GenerateIV();            //Get the key and IV.
            key = myRijndael.Key;
            IV = myRijndael.IV;            //Get an encryptor.
            ICryptoTransform encryptor = myRijndael.CreateEncryptor(key, IV);
            
            //Encrypt the data.
            MemoryStream msEncrypt = new MemoryStream();
            CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write);            //Convert the data to a byte array.
            toEncrypt = textConverter.GetBytes(original);            //Write all data to the crypto stream and flush it.
            csEncrypt.Write(toEncrypt, 0, toEncrypt.Length);
            csEncrypt.FlushFinalBlock();            //Get encrypted array of bytes.
            encrypted = msEncrypt.ToArray();            //This is where the message would be transmitted to a recipient
            // who already knows your secret key. Optionally, you can
            // also encrypt your secret key using a public key algorithm
            // and pass it to the mesage recipient along with the RijnDael
            // encrypted message.                        //Get a decryptor that uses the same key and IV as the encryptor.
            ICryptoTransform decryptor = myRijndael.CreateDecryptor(key, IV);            //Now decrypt the previously encrypted message using the decryptor
            // obtained in the above step.
            MemoryStream msDecrypt = new MemoryStream(encrypted);
            CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read);            fromEncrypt = new byte[encrypted.Length];            //Read the data out of the crypto stream.
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);            //Convert the byte array back into a string.
            roundtrip = textConverter.GetString(fromEncrypt);            //Display the original data and the decrypted data.
            Console.WriteLine("Original:   {0}", original);
            Console.WriteLine("Round Trip: {0}", roundtrip);
        }
    }
}

Answer 3

最简单得加密就是将你得字符串转换成Base64格式
demo
public stataic string ConvertToBase64(string text)
{
  Encoding textConverter=new UnicodeEncoding();
  byte[] resultBuffer=textConverter.GetBytes(text);
  text=Convert.ToBase64String(resultBuffer);//转换成base64字符串！
}

Answer 4

md5 加密好像不能解的吧，des/3des/rsa 没有接触过，可以介绍一下吗？我知道转换ACS码后，是否可以进一步扩展，如加，减，乘，除等运算

Answer 5

完全可以满足你的要求！
http://dotnet.aspx.cc/ShowDetail.aspx?id=7AE7D20A-A5DA-4303-AC2D-32046BE4D086