Cyberwarfare: Information Operations in a Connected World, 2nd Edition

Attacking Cryptography

Attacks against cryptographic systems are conducted in a variety of ways ranging from brute force attacks to stealing or acquiring keys or performing cryptanalysis—the process of finding a weakness in the protocol or key management scheme used for the algorithm or service. Cryptanalysis techniques include analyzing encrypted data to attempt to find patterns, finding vulnerabilities in the underlying cryptographic systems, and even simply trying every possible combination in a cryptosystem to decrypt the message.

The attack type chosen is often based on how much information is available to the attacker. That information is normally classified in one of five ways:

• Ciphertext only, in which the attacker has only one or more ...