Cryptanalysis in cryptographic algorithm design

Abstract

Cryptography is a science of protecting information by changing it into unreadable format (encryption) called ciphertext using a key. The original message can be recovered from the ciphertext by means of decryption. Cryptanalysis deals with the uncovering of encrypted messages without initial knowledge of the key used in the encryption process. These two branches are grouped together, called cryptology. The aim of this paper is to create awareness on the importance of cryptanalysis when designing cryptographic algorithms. The strength of a cryptographic algorithm is not fully dependant on the length of the key. The structure of the cryptographic algorithms must be constructed carefully so that it is resilient against attacks. Therefore, a cryptographic algorithm has to endure cryptanalysis to ensure that it is safe for private or public use. In this paper, we review the types of attacks and focus on short-cut attacks. Short-cut attacks make use of an algorithm’s weaknesses to discover the key faster than brute-force. Brute force is the process of searching for all possible values of the key. Cryptanalysis is vital in measuring a cryptographic algorithm’s resistant towards attacks. It also helps the cryptography community in building more secure algorithms.