# documentation:2.0:authyubikey
Keywords: documentation,2.0,authyubikey

# Yubikey

Authentication | Users | Password
--- | --- | ---
✔ |  |

## Presentation

The Yubikey is a small material token shipped by Yubico. It sends an OTP, which is validated against Yubico server.

You need Auth::Yubikey_WebClient package.

You need to get an client ID and a secret key from Yubico. See Yubico API page.

To use your Yubikeys as “second factor”, use Universal 2nd Factor Authentication (U2F) instead of this module

## Configuration

In Manager, go in `General Parameters` > `Authentication modules` and choose Yubikey for authentication module.

You can then choose any other module for users and password.

Then, go in `Yubikey parameters`:

- Authentication level: authentication level for this module.
- API client ID: API client ID from Yubico
- API secret key: API secret key from Yubico
- OTP public ID part size: Part of Yubikey OTP that will be used as the media identifier (default: 12)

You have to register the media identifier in your user backend (LDAP or SQL) to match the yubikey with a real user. For example it can be stored as a second value of the uid attribute in the LDAP directory:

- uid: coudot
- uid: 123456789012