Simple and lightweight Yubikey OTP and HOTP/OATH validation server to be used with Yubico's Yubikey USB tokens including a powerful administration tool, yubiserver-admin, with which you can manage yubiserver's database by adding,deleting,activating and deactivating users that validate with OTP or HOTP/OATH tokens.

Yubiserver implements Yubico's server side API and can be used with Yubikey USB tokens and any other client that can implement the same API.