It's really great that there are all these voice transmission/encryption programs out there, the problem is, none of them will talk to each other.
Maybe someone could start writing an internet draft about "encrypted voice transmission on the internet". It should address several issues: - compression methods, sampling rate differencies, encoding methods - encryption methods used for bulk data: at least IDEA, 3DES, DES (3DES and DES required, IDEA optional but recommended (for patent reasons)) - key exchange and authentication methods. One good model could be that used in Photuris (see the internet draft draft-ietf-ipsec-photuris-02.txt at e.g. www.ietf.cnri.reston.va.us). Photuris is essentially Diffie-Hellman followed by authenticating the other party via signing the exchange. (Authentication is important to avoid man-in-the-middle attacks). - specification of the protocol for modem-to-modem connections Provided that the compression method is patent-free, all of the related crypto patents expire within about two years (assuming something other than RSA can be used for the signatures - see the Photurs draft). (IDEA should be optional because its patent will not expire in near future). I think it would be a good idea to set up a mailing list for this. Tatu Ylonen <ylo@cs.hut.fi>