Complete Protocol dictionary, glossary and reference

CHAP: Challenge Handshake Authentication Protocol

Challenge Handshake Authentication Protocol (CHAP) is used to periodically verify the identity of the peer using a 3-way handshake. This is done upon initial link establishment and may be repeated any time after the link has been established. CHAP uses a challenge/response authentication mechanism where the response varies every challenge to prevent replay attacks.

Standard Organization

IETF

Related Document

RFC 1994