Encrypting data

Hi,

I want to encrypt data before sending it via an RFC call.

I want to know if there is any function module(or any other way) which can be used to encrypt data based upon the various popular encryption algorithms(like RSA, DES) so that it can be provided as a plugin feature to the client where he can choose whatever algorithm he wants to and is not restricted by my choice.

Please help me and thanks in advance.

Vikas