Summary

In this chapter, we examined the differences between active and passive attacks. We saw how a passive attack is done to either learn information about devices on the network, or pick up confidential information, such as usernames and passwords. We then learned the different types of active attacks, which can modify the integrity of our systems and lead to data loss or compromise.

So that you can understand why encryption is so important, we outlined just what is at risk. We learned the different types of attack vectors, and the different defense mechanisms such as logical and physical security, security appliances, along with policies. Finally, we learned how organizations seek to protect assets and maintain system integrity, and how using countermeasures can reduce vulnerabilities and reduce overall risk.

In the next chapter, we'll discover symmetric encryption. We'll start with briefly covering some of the early ciphers, Lucifer and Feistel, and their influence...