Chapter 6 – Cryptography

Publisher Summary This chapter deals with Systems Security Certified Practitioner exam cryptography. The cryptography area addresses the principles, means, and methods used to disguise information to ensure its integrity, confidentiality, authenticity, and non-repudiation. Cryptography is used as a security tool everywhere these days, from hashed passwords to encrypted mail, to Internet protocol security virtual private networks, and encrypted filesystems. This chapter describes the cryptography used as network security administrators. It focuses on the most common algorithms, including Advanced Encryption Standard, the recently announced new cryptography standard for the U.S. government. The chapter also discusses how key exchanges and public key cryptography come into play and how to use them. The chapter then takes a look at how cryptography can be broken, from cracking passwords to man-in-the-middle-type attacks. The chapter explores how poor implementation of strong cryptography can reduce the security level to zero. Finally, it examines how attempts to hide information using outdated cryptography can easily be broken.