eu uso assim...
aí pra chamar eu faco
strSenhaEncripitada = encript(Senha);
ou
strSenhaDecripitada = Decript(SenhaEncripitada);
private static string sKey;
private static byte[] Buffer;
private static TripleDESCryptoServiceProvider DES;
private static MD5CryptoServiceProvider hashMD5;
private static ICryptoTransform Crypt = null;
private static void prcInicializaCripto()
{
sKey = "SuaChave";
DES = new TripleDESCryptoServiceProvider();
hashMD5 = new MD5CryptoServiceProvider();
DES.Key = hashMD5.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(sKey));
DES.Mode = CipherMode.ECB;
}
public static string Encript(string sValor)
{
prcInicializaCripto();
Crypt = DES.CreateEncryptor();
try
{
Buffer = System.Text.ASCIIEncoding.ASCII.GetBytes(sValor);
}
catch (Exception e)
{
throw e;
}
return Convert.ToBase64String(Crypt.TransformFinalBlock(Buffer, 0, Buffer.Length));
}
public static string Decript(string sValor)
{
prcInicializaCripto();
Crypt = DES.CreateDecryptor();
try
{
Buffer = Convert.FromBase64String(sValor);
}
catch (Exception e)
{
throw e;
}
return System.Text.ASCIIEncoding.ASCII.GetString(Crypt.TransformFinalBlock(Buffer, 0, Buffer.Length));
}