Question details:

Week Four Assignment – Write a 1000 word paper addressing the following:

Explain the seven layers of the OSI model in detail.

At which layers do packet-filtering routers and firewalls reside? And how do pack-filtering routers and firewalls protect a network?

Explain the concept of cryptography. What are the various types of cryptography? Summarize the mechanisms that make up a strong cryptosystem and how the cryptosystem could be used to secure a system.