mod_auth_pubtkt is a simple Web single sign-on (SSO) solution for Apache. It validates authentication tickets provided by the client in a cookie using public-key cryptography (DSA or RSA). Thus, only the login server that generates the tickets needs to possess the private key, while Web servers can verify tickets given only the public key. The implementation of the login server is left to the user, but an example and a library in PHP are provided with the distribution.
