加密解密算法，太常用了，可是实在忍受不了十次八次之后还是要重头写，总是能告诉我原来的算法不好用（实际是压根不会用）的情况，不如直接写出来，再有人要直接给他看看，也顺便记录下算法，方便下新手大众。

DES算法：这算是大家非常常用的对称算法了，很多人都在用这个。

private static string DesKey = @"P@+#wG+Z";/// 
         /// DES加密字符串         /// 
         /// 待加密的字符串         /// 加密密钥,要求为8位         /// 
     
      加密成功返回加密后的字符串，失败返回源串
              public static string EncryptDES(string encryptString, string encryptKey)        {            try            {                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));                byte[] rgbIV = Keys;                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();                MemoryStream mStream = new MemoryStream();                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);                cStream.Write(inputByteArray, 0, inputByteArray.Length);                cStream.FlushFinalBlock();                return Convert.ToBase64String(mStream.ToArray());            }            catch            {                return encryptString;            }        }        /// 
         /// DES解密字符串         /// 
         /// 待解密的字符串         /// 解密密钥,要求为8位,和加密密钥相同         /// 
     
      解密成功返回解密后的字符串，失败返源串
              public static string DecryptDES(string decryptString, string decryptKey)        {            try            {                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);                byte[] rgbIV = Keys;                byte[] inputByteArray = Convert.FromBase64String(decryptString);                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();                MemoryStream mStream = new MemoryStream();                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);                cStream.Write(inputByteArray, 0, inputByteArray.Length);                cStream.FlushFinalBlock();                return Encoding.UTF8.GetString(mStream.ToArray());            }            catch            {                return decryptString;            }        }

DesKey 就是秘钥，这个看自己喜欢了，鄙人也曾经用过“wlyzdhp”之类的秘钥。

AES算法：也是常用的对称算法，安全系数比DES好一点。个人很推荐使用。

private static string AesKey = @")O[NB]6,YF}+efcaj{+oESb9d8>Z'e9M"; /// 
        /// AES 加密(高级加密标准，是下一代的加密算法标准，速度快，安全级别高，目前 AES 标准的一个实现是 Rijndael 算法)        /// 
        /// 待加密密文        /// 加密密钥        /// 
             public static string AESEncrypt(string EncryptString, string EncryptKey)        {            if (string.IsNullOrEmpty(EncryptString)) { throw (new Exception("密文不得为空")); }            if (string.IsNullOrEmpty(EncryptKey)) { throw (new Exception("密钥不得为空")); }            string m_strEncrypt = "";            byte[] m_btIV = Convert.FromBase64String("Rkb4jvUy/ye7Cd7k89QQgQ==");            Rijndael m_AESProvider = Rijndael.Create();            try            {                byte[] m_btEncryptString = Encoding.Default.GetBytes(EncryptString);                MemoryStream m_stream = new MemoryStream();                CryptoStream m_csstream = new CryptoStream(m_stream, m_AESProvider.CreateEncryptor(Encoding.Default.GetBytes(EncryptKey), m_btIV), CryptoStreamMode.Write);                m_csstream.Write(m_btEncryptString, 0, m_btEncryptString.Length);                m_csstream.FlushFinalBlock();                m_strEncrypt = Convert.ToBase64String(m_stream.ToArray());                m_stream.Close(); m_stream.Dispose();                m_csstream.Close(); m_csstream.Dispose();            }            catch (IOException ex) { throw ex; }            catch (CryptographicException ex) { throw ex; }            catch (ArgumentException ex) { throw ex; }            catch (Exception ex) { throw ex; }            finally { m_AESProvider.Clear(); }            return m_strEncrypt;        }        /// 
        /// AES 解密(高级加密标准，是下一代的加密算法标准，速度快，安全级别高，目前 AES 标准的一个实现是 Rijndael 算法)        /// 
        /// 待解密密文        /// 解密密钥        /// 
             public static string AESDecrypt(string DecryptString, string DecryptKey)        {            if (string.IsNullOrEmpty(DecryptString)) { throw (new Exception("密文不得为空")); }            if (string.IsNullOrEmpty(DecryptKey)) { throw (new Exception("密钥不得为空")); }            string m_strDecrypt = "";            byte[] m_btIV = Convert.FromBase64String("Rkb4jvUy/ye7Cd7k89QQgQ==");            Rijndael m_AESProvider = Rijndael.Create();            try            {                byte[] m_btDecryptString = Convert.FromBase64String(DecryptString);                MemoryStream m_stream = new MemoryStream();                CryptoStream m_csstream = new CryptoStream(m_stream, m_AESProvider.CreateDecryptor(Encoding.Default.GetBytes(DecryptKey), m_btIV), CryptoStreamMode.Write);                m_csstream.Write(m_btDecryptString, 0, m_btDecryptString.Length);                m_csstream.FlushFinalBlock();                m_strDecrypt = Encoding.Default.GetString(m_stream.ToArray());                m_stream.Close(); m_stream.Dispose();                m_csstream.Close(); m_csstream.Dispose();            }            catch (IOException ex) { throw ex; }            catch (CryptographicException ex) { throw ex; }            catch (ArgumentException ex) { throw ex; }            catch (Exception ex) { throw ex; }            finally { m_AESProvider.Clear(); }            return m_strDecrypt;        }

同上，不解释了。

RSA算法：RSA算法是用一套公钥秘钥进行加密解密的，从安全机制上来说比上面两种好，不过这种算法是基于两个大质数乘积互质原则来进行加密解密的，效率上跟公钥秘钥的大小有关，看官们可以根据情况适用，这里只给出了一套我现在常用的一套公钥秘钥，公钥秘钥网上有相关的生成软件，各位可以自行下载使用。

/// 
        /// RSA加密        /// 
        ///         ///         /// 
             public static string RSAEncrypt(string publickey, string content)        {            publickey = @"
     
      
       5m9m14XH3oqLJ8bNGw9e4rGpXpcktv9MSkHSVFVMjHbfv+SJ5v0ubqQxa5YjLN4vc49z7SVju8s0X4gZ6AzZTn06jzWOgyPRV54Q4I0DCYadWW4Ze3e+BOtwgVU1Og3qHKn8vygoj40J6U85Z/PTJu3hN1m75Zr195ju7g9v4Hk=
      
      
       AQAB
      
     ";            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();            byte[] cipherbytes;            rsa.FromXmlString(publickey);            cipherbytes = rsa.Encrypt(Encoding.UTF8.GetBytes(content), false);            return Convert.ToBase64String(cipherbytes);        }        /// 
        /// RSA解密        /// 
        ///         ///         /// 
             public static string RSADecrypt(string privatekey, string content)        {            privatekey = @"
     
      
       5m9m14XH3oqLJ8bNGw9e4rGpXpcktv9MSkHSVFVMjHbfv+SJ5v0ubqQxa5YjLN4vc49z7SVju8s0X4gZ6AzZTn06jzWOgyPRV54Q4I0DCYadWW4Ze3e+BOtwgVU1Og3qHKn8vygoj40J6U85Z/PTJu3hN1m75Zr195ju7g9v4Hk=
      
      
       AQAB
      
      
/hf2dnK7rNfl3lbqghWcpFdu778hUpIEBixCDL5WiBtpkZdpSw90aERmHJYaW2RGvGRi6zSftLh00KHsPcNUMw==
      6Cn/jOLrPapDTEp1Fkq+uz++1Do0eeX7HYqi9rY29CqShzCeI7LEYOoSwYuAJ3xA/DuCdQENPSoJ9KFbO4Wsow==
      
       ga1rHIJro8e/yhxjrKYo/nqc5ICQGhrpMNlPkD9n3CjZVPOISkWF7FzUHEzDANeJfkZhcZa21z24aG3rKo5Qnw==
      
      
       MNGsCB8rYlMsRZ2ek2pyQwO7h/sZT8y5ilO9wu08Dwnot/7UMiOEQfDWstY3w5XQQHnvC9WFyCfP4h4QBissyw==
      
      
       EG02S7SADhH1EVT9DD0Z62Y0uY7gIYvxX/uq+IzKSCwB8M2G7Qv9xgZQaQlLpCaeKbux3Y59hHM+KpamGL19Kg==
      
      
       vmaYHEbPAgOJvaEXQl+t8DQKFT1fudEysTy31LTyXjGu6XiltXXHUuZaa2IPyHgBz0Nd7znwsW/S44iql0Fen1kzKioEL3svANui63O3o5xdDeExVM6zOf1wUUh/oldovPweChyoAdMtUzgvCbJk1sYDJf++Nr0FeNW1RB1XG30=
      
     ";            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();            byte[] cipherbytes;            rsa.FromXmlString(privatekey);            cipherbytes = rsa.Decrypt(Convert.FromBase64String(content), false);            return Encoding.UTF8.GetString(cipherbytes);        }

 

 

总结：加密解密算法博大精深，这里只是为了我们使用起来方便，有现成的算法（即使这样依然有人敢告诉我这个方法不知道怎么调用）供我们快速调用，对于秘钥本身这里不做过多探讨了，有兴趣的我们可以过后研究交流。鄙人也是初涉加密解密领域，各种不足，各位看官轻喷。