Chapter 11. Introduction to Applied Cryptography: Symmetric Ciphers

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—Karamazoff bro

Cryptography underlies network security, yet many system administrators and IT security consultants know little about its inner workings, strength and efficiency of various ciphers available, and optimal conditions for their implementation. Almost all publications on cryptography are split into two large categories:

• Those that explain the mathematical side of cryptography in great detail and are difficult to digest for a system administrator or IT consultant.

• Those that try to explain cryptography without a single formula and simply feed the ideas resulting from the mathematical machinery at work without an explanation and are oversimplified.

The next two chapters are an attempt to bridge this gap. Besides, we hope that it makes interesting bedtime reading for experts on the networking and system administration side and IT consultants. Furthermore, this is probably the only publication on cryptography that does not mention Bob and Alice (apart from this very sentence). What a relief!