Security Protocols

Introduction

All the security principles and concepts discussed in the previous two chapters can be used to provide all aspects of security for the Internet model.

In particular, security measures can be applied to the network layer, transport layer, and application layer.

At the IP layer, implementation of security features is Very complicated, especially since every device must be enabled.

IP provides services not only for user applications, but also for other protocols such as OSPF, ICMP, and IGMP.

This means that implementation of security at this level is not very effective unless all devices are equipped to use it.

We discuss a protocol called IPSec that provides security at the IP level.

At the transport layer, security is even more complicated. We could modify the application or modify the transport layer for security.

Instead, we discuss a protocol that "glues" a new layer to the transport layer to provide security on behalf of the transport layer.

At the application layer, each application is responsible for providing security. The implementation of security at this level is the simplest.

It concerns two entities: the client and the server. We discuss a security method at the application layer called PGP.

A mechanism often used to ensure the integrity of an organization is a firewall. We give a brief discussion of firewalls in this chapter.