Yubico distributes a device called Yubikey to provide One Time Passwords (OTP). To verify provided OTPs, this package implements a C library for access to the authentication service.
Created attachment 205492 [details] ebuild for sys-libs/ykclient-2.3
This bug should be closed. ykclient-2.3 (out of date) exists in portage under sys-auth/ykclient.
In the tree as noted in comment #2.