CISSP 11.9 - Secure Communication Protocols

This episode of the ISC2 Certified Information Systems Security Professional (CISSP) exam prep series meets the Domain 4 protocols that add security to specific channels. Choosing the right one is a routine design decision, and knowing what each protocol was built to secure lets you match the tool to the channel with confidence rather than leaving a gap.

Frequently Asked Questions

What makes a protocol a secure communication protocol?

It provides security services for a specific kind of communication channel. Rather than one universal shield, each of these protocols adds protection tailored to a particular job, whether that is a private tunnel, a login, a message, or a remote command. The common thread is that they layer confidentiality, integrity, or authentication onto communications that would otherwise travel exposed, like specialized locks each shaped for a different door.

What does the internet protocol security suite provide?

It provides a full bundle of protections built directly on the addressing layer. It uses public key cryptography to deliver encryption, integrity, replay protection, access control, and verification of where a message came from. Its main use is building private tunnels, and it can operate in two modes, one protecting just the payload and one protecting the whole packet. It is a bolt-on for the older address version but native to the newer one.

How do the single sign-on and remote-shell protocols protect access?

By guarding credentials and sessions. The single sign-on protocol lets a user authenticate once and reach many services, protecting the logon credentials with strong, modern cryptography so passwords are not exposed on the network. The remote-shell protocol is a strong example of end-to-end encryption that wraps insecure legacy utilities in a protected channel, secures file transfers, and can even act as a host-to-host tunnel.

What secures messaging and remote calls?

Two purpose-built protocols. The messaging protocol provides end-to-end encryption for voice, video, and text and is the cryptographic core inside a well-known secure messaging application, ensuring only the two endpoints can read the exchange. The secure remote procedure call protocol is an authentication service for communication between services across a network, guarding against unauthorized code being run on remote systems.

What does transport layer security do?

It is the workhorse encryption protocol that secures traffic at the transport layer by protecting the payload of reliable connections. You know it best as the encryption behind secure web browsing, but it can protect almost any application-layer protocol. It blocks tampering, spoofing, and eavesdropping, offers one-way or, with certificates, two-way authentication, and it replaced the older, now-retired secure sockets layer.

Reference: This article is based on concepts discussed in CISSP 11.9 - Secure Communication Protocols.