openssh two factor authentication



Hi

I have one server (ubuntu server 7.04, openssh) and I would like to be asked about password and then an extra question.
The extra question should be somthing the user knows and changes with time (example today is 31-10-2007 so the user
would type in 61 (2*day-1 2*31-1 = 61)

Thorir
Iceland
.