Security in Computing, Third Edition

Chapter 10. Cryptography Explained

In this chapter:

• Mathematics of encryption

• Cryptanalysis: how encryption systems are “broken”

• Theory of strong symmetric algorithms

• Detailed descriptions of the DES and AES algorithms

• Theory of public key encryption

• Detailed description of the RSA algorithm; details of other public key algorithms

• Digital signatures

• Quantum cryptography

Creating and implementing good cryptography is subtle and difficult, because the goals of a cryptographic algorithm seem to conflict with each other. We want to construct an algorithm that is easy for the legitimate sender and receiver to operate, but difficult—bordering on impossible—for the malicious interceptor to break. As we noted in Chapter 2, the interceptor can use any kind ...