HP48 Crypto

[Dan McGuirk]

I'm interested in finding out what cryptographic tools, if any, are
available for the HP48 calculator.  I think someone mentioned that
they were developing a challenge authentication system using the HP48
to ameliorate the problem of sending cleartext passwords during telnet
sessions.  Is this project still being worked on?  Also, are there any
multiple-precision math libraries available for the 48?

Thanks for any information...