Introduction to Cryptanalysis Attacks on Symmetric Ciphers

Cryptanalysis is the science and techniques of analyzing and breaking cryptographic algorithms and protocols. There exist hundreds of cryptanalysis attack variants. Cryptanalysis is a very exciting field; and improvements of existing attacks are proposed every year. Cryptanalysis attacks can be categorized according to various criteria. This chapter aims at introducing some common methods used to attack symmetric ciphers, namely: memory‐time trade‐off attacks, including Hellman's tables and rainbow chains; linear cryptanalysis; differential cryptanalysis; algebraic cryptanalysis; cube attacks; divide‐and‐conquer attacks; and correlation attacks. Three metrics are commonly used to assess the complexities of attacks: computation time, memory to store data (plaintexts, ciphertexts, and others), and the number of known/chosen plaintexts and/or ciphertexts. Those metrics are briefly discussed in this chapter, because huge parameters are often required to describe attack complexities.