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Types of Information Security Protocols

Name: 8.4 Types of Information Security Protocols — System Analysis and Design
Uploaded: 2026-09-28T09:59:25+00:00
Duration: 7 min 22 s
Description: TLS, IPsec, SSH, Kerberos, WPA3, and S/MIME - and the layer where each one works

System Analysis and Design · Chapter 8: Maintenance, Risk, and SecuritySection 8.4 · lesson 56 of 697 min · free with a free account

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In this lesson

TLS, IPsec, SSH, Kerberos, WPA3, and S/MIME - and the layer where each one works.

Explain why security protocols operate at different network layers
Identify what TLS/HTTPS, IPsec, SSH/SFTP, Kerberos, WPA3, and S/MIME protect
Place each protocol at the layer where it operates
Match a security scenario to the protocol best suited to it

Transcript

Everything said in the video, section by section (1,041 words). Read along, or search it.

Maintenance, Risk, and Security

Information Security Protocols

Data is exposed at many points on its journey, from an application, across networks, and over the air. This section surveys six widely used security protocols, and places each one at the network layer where it operates. By the end, you should be able to match a security scenario to the protocol best suited to it.

No Single Protocol

Protection at Different Points

No single protocol secures an entire system. Instead, different protocols protect data at different points as it travels. Some protect the content of one specific application. Others protect every packet crossing a network. Others protect the wireless link itself. A useful way to organize them is by the network layer where they operate. Protocols higher in the stack protect the content that a specific application sends. Protocols lower in the stack protect data more broadly, regardless of which application produced it.

Figure 1

6 Protocols, 4 Layers

Here are the six protocols, placed on four layers. At the application layer sit S S H and S F T P, Kerberos, and S MIME. At the transport layer sits T L S, which is what H T T P S runs on. At the network layer sits I P sec. And at the data link layer sits W P A three, securing the wireless connection itself. Moving down the stack, protection gets broader. From one application's content, to everything crossing the link.

At a Glance

What Each Protocol Protects

Here is what each one protects. T L S, and H T T P S, at the transport layer, encrypt and authenticate a connection between a client and a server. I P sec, at the network layer, encrypts and authenticates individual I P packets as they cross a network. S S H and S F T P, at the application layer, secure a remote login session, and file transfers within it. Kerberos, also at the application layer, authenticates users and services with time-limited tickets, instead of passwords sent over and over. W P A three, at the data link layer, encrypts traffic between a device and a wireless access point. And S MIME, at the application layer, encrypts and digitally signs the content of an email message.

A Closer Look (1 of 3)

TLS / HTTPS and IPsec

Now a closer look at each. T L S, transport layer security, encrypts and authenticates a connection, so data traveling over it cannot be read or altered in transit. H T T P S is simply H T T P, running on top of a T L S connection. The padlock in a browser's address bar means T L S is protecting the page. So checking a bank balance behind that padlock relies on T L S. I P sec, internet protocol security, works one layer lower. It encrypts and authenticates traffic packet by packet, whatever application created it. Because it protects everything crossing a connection, it is the usual choice for building virtual private networks between sites. Connect two offices this way, and every application's traffic between them is encrypted, with no need to configure each application.

A Closer Look (2 of 3)

SSH / SFTP and Kerberos

S S H, secure shell, provides an encrypted channel for logging into, and running commands on, a remote machine. S F T P, the S S H file transfer protocol, reuses that same encrypted channel to transfer files securely. That is why the two are almost always mentioned together. An administrator logs in with S S H, then copies a file with S F T P, over the same secure channel. Kerberos authenticates users and services using time-limited tickets, issued by a trusted server. After the first login, it is the ticket, not the password, that is presented to each additional system. So credentials cross the network less often, and a user can reach several internal systems after authenticating just once.

A Closer Look (3 of 3)

WPA3 and S/MIME

W P A three, Wi-Fi protected access three, encrypts traffic between a device and a wireless access point. It protects that traffic from anyone else within range of the same network. It is the current standard for securing wireless networks, replacing the older and weaker W P A two. S MIME, secure multipurpose internet mail extensions, encrypts the body of an email, so only the intended recipient can read it. It can also digitally sign a message, proving it really came from the claimed sender, and was not altered in transit.

Putting It to Work

Match the Scenario to the Protocol

Let's put this to work, matching scenarios to protocols. Two office networks connect over the internet, with every application's traffic between them encrypted automatically. That is I P sec, working at the network layer. A padlock appears in the browser while someone checks a bank balance. That is T L S, at the transport layer. An employee logs in once in the morning, then reaches several internal systems all day without a password. That is Kerberos, and its tickets. An administrator logs into a remote server, then copies a configuration file to it. That is S S H, then S F T P, over the same channel. And an office buys a new router, to better protect traffic between laptops and the access point. That is W P A three, at the data link layer.

Key Terms

The Vocabulary of This Section

Let's lock in the key terms. T L S secures a connection between a client and a server. H T T P S is H T T P running over T L S. I P sec secures individual I P packets, and is commonly used for V P Ns. S S H provides an encrypted remote login. S F T P transfers files over an S S H connection. Kerberos authenticates with time-limited tickets. W P A three is the current standard for securing a wireless link. And S MIME encrypts and digitally signs the content of an email.

Key Takeaways

What to Carry Forward

To pull this together. Security protocols operate at different network layers, protecting either one application's content, or everything crossing a connection. T L S secures a transport connection, and H T T P S is H T T P running over it. I P sec secures individual packets at the network layer, making it well suited to site-to-site V P Ns. S S H secures remote logins, and S F T P reuses that encrypted channel for file transfers. Kerberos authenticates with time-limited tickets, rather than repeatedly sending passwords. And W P A three secures the wireless link itself, while S MIME secures the content of an individual email.

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FAQ

Questions students ask us

About Types of Information Security Protocols

What is the difference between TLS and HTTPS?

TLS, or transport layer security, is a protocol that encrypts and authenticates a connection between a client and a server, while HTTPS is simply HTTP running on top of a TLS connection. The padlock in a browser's address bar indicates that TLS is protecting the page, so data such as a bank balance cannot be read or altered in transit.

What is IPsec used for?

IPsec, or internet protocol security, encrypts and authenticates traffic packet by packet at the network layer, whatever application created it. Because it protects everything crossing a connection, it is a common choice for virtual private networks, including site-to-site VPNs linking two offices. Once configured, every application's traffic between the sites is encrypted without setting up each application separately.

How does Kerberos authentication work?

Kerberos authenticates users and services with time-limited tickets issued by a trusted server instead of sending a password repeatedly. After the first login, the ticket rather than the password is presented to each additional system. That means credentials cross the network less often, and a user who signs in once in the morning can reach several internal systems through the day.

What is the difference between SSH and SFTP?

SSH, or secure shell, provides an encrypted channel for logging into and running commands on a remote machine, while SFTP, the SSH file transfer protocol, uses that encrypted channel to transfer files. That is why the two are usually mentioned together. An administrator might log into a remote server with SSH and then copy a configuration file to it with SFTP.

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