求教：des算法的原理？？

[yes4pierce]

如题，des 加密，解密的算法的原理是什么，请不吝赐教。
在C#中，怎样对字符实现des加密，解密？？

[cnming]

原理是按位异或、移位等等组合的复杂算法，在C#中，有System.Security.Cryptography的名称空间，里头支持DES算法，所以不用你写了

[cnming]

我的blog，关于DES的

http://blog.csdn.net/cnming/archive/2004/12/09/210437.aspx

你指定好密钥即可，当然你要了解密钥的概念，DES是对称密钥的加密解密算法

#region TripleDES算法

public class ClassTripleDES
{
public ClassTripleDES()
{
}

//加密，使用密码产生加密算法的公钥，并使用TripleDES对密码进行加密。
public static string Encrypt(string pass)
{
try
{
byte[] bt = (new System.Text.UnicodeEncoding()).GetBytes(pass);
PasswordDeriveBytes pdb = new PasswordDeriveBytes(pass, null);
byte[] key = pdb.GetBytes(24);
byte[] iv = pdb.GetBytes(8);
MemoryStream ms = new MemoryStream();
TripleDESCryptoServiceProvider tdesc = new TripleDESCryptoServiceProvider();
CryptoStream cs = new CryptoStream(ms,tdesc.CreateEncryptor(key, iv),CryptoStreamMode.Write);
cs.Write(bt, 0, bt.Length);
cs.FlushFinalBlock();
return Convert.ToBase64String(ms.ToArray());
}
catch(Exception ex)
{
throw ex;
}
}

//解密，使用密码产生加密算法的公钥，并使用TripleDES对加密数据进行解密。
public static string Decrypt(string str, string pass)
{
try
{
byte[] bt = Convert.FromBase64String(str);
PasswordDeriveBytes pdb = new PasswordDeriveBytes(pass, null);
byte[] key = pdb.GetBytes(24);
byte[] iv = pdb.GetBytes(8);
MemoryStream ms = new MemoryStream();
TripleDESCryptoServiceProvider tdesc = new TripleDESCryptoServiceProvider();
CryptoStream cs = new CryptoStream(ms,tdesc.CreateDecryptor(key, iv),CryptoStreamMode.Write);
cs.Write(bt, 0, bt.Length);
cs.FlushFinalBlock();
return (new System.Text.UnicodeEncoding()).GetString(ms.ToArray());
}
catch(Exception ex)
{
throw ex;
}
}
//使用：
//string str = Encrypt("bbb");
//Console.WriteLine(Decrypt(str, "bbb"));

//加密，使用密码产生加密算法的公钥，并使用TripleDES对密码进行加密。
public static string EncryptWithKey(string pass, string p_key)
{
try
{
byte[] bt = (new System.Text.UnicodeEncoding()).GetBytes(pass);
PasswordDeriveBytes pdb = new PasswordDeriveBytes(p_key, null);
byte[] key = pdb.GetBytes(24);
byte[] iv = pdb.GetBytes(8);
MemoryStream ms = new MemoryStream();
TripleDESCryptoServiceProvider tdesc = new TripleDESCryptoServiceProvider();
CryptoStream cs = new CryptoStream(ms,tdesc.CreateEncryptor(key, iv),CryptoStreamMode.Write);
cs.Write(bt, 0, bt.Length);
cs.FlushFinalBlock();
return Convert.ToBase64String(ms.ToArray());
}
catch(Exception ex)
{
throw ex;
}
}

//解密，使用密码产生加密算法的公钥，并使用TripleDES对加密数据进行解密。
public static string DecryptWithKey(string str, string p_key)
{
try
{
byte[] bt = Convert.FromBase64String(str);
PasswordDeriveBytes pdb = new PasswordDeriveBytes(p_key, null);
byte[] key = pdb.GetBytes(24);
byte[] iv = pdb.GetBytes(8);
MemoryStream ms = new MemoryStream();
TripleDESCryptoServiceProvider tdesc = new TripleDESCryptoServiceProvider();
CryptoStream cs = new CryptoStream(ms,tdesc.CreateDecryptor(key, iv),CryptoStreamMode.Write);
cs.Write(bt, 0, bt.Length);
cs.FlushFinalBlock();
return (new System.Text.UnicodeEncoding()).GetString(ms.ToArray());
}
catch(Exception ex)
{
throw ex;
}
}

}

#endregion

[fanruinet]

http://www.50yi.com/book/bczl/200409/98.html

[nga96]

建议先看看密码学吧，那是门很深的学问的