http://www.rfc-editor.org/rfc/rfc6560.txt
RFC 6560: One-Time Password (OTP) Pre-Authentication, G. Richards2012-04-01T23:00:00-00:00The Kerberos protocol provides a framework authenticating a client using the exchange of pre-authentication data. This document describes the use of this framework to carry out One-Time Password (OTP) authentication. [STANDARDS-TRACK]