Implementacija Rijndael-a postoji kao deo standardnog framework-a, System.Security.Cryptography namespace, klase Rijndael (abstract) i RijndaelManaged. Za TwoFish pogledaj
CodeProject i, naravno,
Google 
If it's a girl then they're gonna call it Sigourney, after an actress. If it's a boy, then they're gonna call it Rodney, after Dave!