I'm investigating the possibility of using a phone for the purposes of authenticating the identity of a person at a laptop using an IrDA connection (point and fire type of thing).

I want to know if it is possible to use an IrDA connection between a laptop and a Nokia phone to access crypto functions on the phone to generate a digital signature (proof of possesion of a private key stored on the SIM). I'm looking for the laptop to initiate the connection with the phone and the user seeing a message request them to authenticate him/her self, then entering a PIN at which point the signature is generated and returned to the laptop.

From my investigations so far, looks like the PC connectivity won't do it, but using WAP push type stuff might do this.

Possible? Has anybody considered it/done anything similar? Are there any other possibilities?