Yubikeys are usb tokens that act like keyboards and generate one-time passwords (otps). the tokens are produced and sold by yubico.

this library is used for talking to an online validation server such as yubikey-server-c, yubikey-server-php or yubikey-server-j.

this package contains the necessary files for developers, and a command line tool "ykclient" to perform otp queries from the shell.