Algorithm Type Class to Instantiate
DES Symmetric DESCryptoServiceProvider
RC2 Symmetric RC2CryptoServiceProvider
Rijndael Symmetric RijndaelManaged
Triple DES Symmetric TripleDESCryptoServiceProvider
DSA Asymmetric DSACryptoServiceProvider
RSA Asymmetric RSACryptoServiceProvider

Table 1 Instantiate an Algorithm's Managed Class. Each encryption algorithm the .NET Framework supports inherits from either SymmetricAlgorithm or AsymmetricAlgorithm within the System.Security.Cryptography namespace. You must instantiate and use a special managed class when you write applications to use any of these algorithms.