This is a reasonable assumption in practice - throughout history, there are countless examples of secret algorithms falling into wider knowledge, variously through espionage, betrayal and reverse engineering. As a basic starting point it is normally assumed that, for the purposes of analysis, the general algorithm is known this is Shannon's Maxim "the enemy knows the system" - in its turn, equivalent to Kerckhoffs' principle. Cryptographic attacks can be characterized in a number of ways:Īmount of information available to the attacker Īttacks can be classified based on what type of information the attacker has available. Given some encrypted data ( " ciphertext"), the goal of the cryptanalyst is to gain as much information as possible about the original, unencrypted data ( " plaintext").
In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation.
Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown. Close-up of the rotors in a Fialka cipher machineĬryptanalysis (from the Greek kryptós, "hidden", and analýein, "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems.