Fundamentals of Information Systems Security, 4th Edition

Principles of Certificates and Key Management

You learned about key management earlier in the chapter, that it includes creating, distributing, storing, validating, updating, replacing, and revoking keys and keying material.

Here is a sample classic key management scheme. The Enigma was one of the most famous cryptographic devices of the 20th century. Invented by Arthur Scherbius, it was Germany’s chief encryption tool before and during World War II. The machine had more possible keying configurations than the number of atoms in the known universe. In practice, a subset of keys was used to make key changing practical. Nonetheless, the three-rotor Enigma offered a dizzying 158,962,555,217,826,360,000 possible keys at the beginning of World War ...