PAP, CHAP, and MS-CHAP - CompTIA Security+ SY0-501 - 4.2

PAP, CHAP, and MS-CHAP - CompTIA Security+ SY0-501 - 4.2

Point-to-Point Protocol (PPP)

This section discusses the Point-to-Point Protocol (PPP) and its derivatives, including PPTP and PPPoE. It also covers authentication methods such as PAP, CHAP, and MS-CHAP.

PPP and Its Derivatives

  • PPP is used for authentication on analog dial-up, ISDN, and other types of Point-to-Point Networks.
  • PPTP is a derivative of PPP commonly used in Windows operating systems.
  • PPPoE is another derivative of PPP commonly used to authenticate over a DSL network.

Authentication Methods

Password Authentication Protocol (PAP)

  • PAP is one of the most basic authentication methods.
  • It communicates in clear text without encryption or additional security measures.
  • It was commonly used on old or legacy systems but is now rarely used by itself.

Challenge Handshake Authentication Protocol (CHAP)

  • CHAP was created to provide additional security to the authentication process.
  • It uses an encrypted challenge to send credentials across the network.
  • It uses a three-way handshake to authenticate users.

Microsoft CHAP (MS-CHAP)

  • MS-CHAP is a customized version of CHAP developed by Microsoft.
  • The most recent version is referred to as MS_CHAP v2.
  • Unfortunately, both versions suffer from vulnerabilities due to the use of DES protocol.

Alternatives

Many people have migrated from using MS_CHAP due to its vulnerabilities. Instead, they use L2TP, IPsec or some other type of secure VPN communication.