C# 关于DESC加密 求简单例子一个

Question

已知密钥String sKey，求加密算法，最主要是注释详细点.

Answer 1

        public static string DesDecode(string data)
        {
            byte[] buffer3;
            byte[] bytes = Encoding.ASCII.GetBytes("key");
            byte[] rgbIV = Encoding.ASCII.GetBytes("key");
            try
            {
                buffer3 = Convert.FromBase64String(data);
            }
            catch
            {
                return null;
            }
            DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
            MemoryStream stream = new MemoryStream(buffer3);
            CryptoStream stream2 = new CryptoStream(stream, provider.CreateDecryptor(bytes, rgbIV), CryptoStreamMode.Read);
            StreamReader reader = new StreamReader(stream2);
            return reader.ReadToEnd();
        }        public static string DesEncode(string data)
        {
            byte[] bytes = Encoding.ASCII.GetBytes("key");
            byte[] rgbIV = Encoding.ASCII.GetBytes("key");
            DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
            int keySize = provider.KeySize;
            MemoryStream stream = new MemoryStream();
            CryptoStream stream2 = new CryptoStream(stream, provider.CreateEncryptor(bytes, rgbIV), CryptoStreamMode.Write);
            StreamWriter writer = new StreamWriter(stream2);
            writer.Write(data);
            writer.Flush();
            stream2.FlushFinalBlock();
            writer.Flush();
            return Convert.ToBase64String(stream.GetBuffer(), 0, (int)stream.Length);
        }