CHAP is an authentication scheme used by Point-to-Point Protocol (PPP) servers to validate the identity of remote clients. CHAP periodically verifies the identity of the client by using a three-way handshake

CHAP – Challenge Handshake Authentication Protocol

1) Send user ID in

the clear

Client System

CHAP Server

gkessler

2) Send random

string:

calculate hash value of string and password:

1bRQv#7

Af329Z@$$8*k52

1bRqv#71

3) Return hash

value of random

string and

password

4) Compare

response

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