Remote Access Authentication Protocols

By Stephen Bucaro

A remote access authentication protocol is the method by which remote users will be authenticated when they log on the network. One (unwise) choice is to allow users to log on without authentication.

Extensible Authentication Protocol (EAP)

EAP allows for authentication of a remote access connection through the use of authentication schemes, known as EAP types. EAP offers the strongest security by providing the most flexibility in authentication variations. EAP can support authentication mechanisms, such as token cards, smart cards, certificates, and public key encryption authentication.

Challenge Handshake Authentication Protocol (CHAP)

CHAP enables authentication without having the user send their password over the connection. The server sends a challenge message to the connection requester. The requester responds with a value obtained by using the industry-standard Message Digest 5 (MD5) hashing scheme to encrypt the response. The server checks the response by comparing it its own calculation of the expected hash value. MS-CHAP, which supports only Windows Servers, works the same way as CHAP.

Password Authentication Protocol (PAP)

PAP is the least secure authentication protocol. The username and password is sent in plaintext. It does not protect against anyone listening to network traffic from stealing the username and password. It is used only when the remote access client or the remote access server cannot negotiate a more secure form of validation.

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• Implementing a Secure Password Policy
• Wireless Network Security - The Basics of Securing a Wireless LAN
• What is Network AAA (Authentication, Authorization, and Accounting)?
• Essentials of Endpoint Device Backup
• Handling Rogue Access Points
• Why Become a CISSP?
• Firewall Rules

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