This package provides the yubico pam module. it enables the use of two-factor authentication, with existing logins and passwords plus a yubikey one-time password that is validated against an online validation service. the default is the free yubicloud, but it is easy to set up a custom service.

a second mode of operation is available using the yubikey's hmac-sha-1 challenge-response functionality. this allows for offline validation using a yubikey, for example on a laptop computer. however, this only works for local logins, not for instance ssh logins.