What is Differential Cryptanalysis in Information Security?

Differential cryptanalysis is a general model of cryptanalysis applicable generally to block ciphers, but it can also to stream ciphers and cryptographic hash functions. In the largest sense, it is the study of how differences in data input can influence the resultant difference at the output.

The main objective of differential cryptanalysis is to view for statistical distributions and patterns in ciphertext to provide deduce details about the key used in the cipher.

Differential cryptanalysis is a section of study in cryptography that compares the method differences in input associated to the differences in encrypted output. It can be used basically in the study of block ciphers to determine if changes in plaintext result in any non-random outcome in the encrypted ciphertext.

This process is essential because non-random changes to the ciphertext can indicate a weakness in the encryption scheme. An unauthorized third-party can gain information about what was encrypted or how it was encrypted by inspecting information changes.

In block cipher, differential analysis can be defined as a group of techniques for tracing differences through the network of transformation, finding where the cipher exhibits what is called a non-random behavior and exploiting such element to retrieve the secrete key (cryptography key).

For any specific cipher, the input difference should be severely selected for the attack to be successful. An analysis of the algorithm’s internals is undertaken and the standard approach is to trace a route of highly probable differences through the various process of encryption, defined as differential characteristic.

In the procedure, observing the desired output difference between the two chosen or unknown plaintext inputs recommend possible key values.

Differential cryptanalysis was firstly introduced by Biham and Shamir to interpret DES block cipher in 1990. Differential analysis is one of the most efficient attack methods in block ciphers.

Differential analysis is a selective plaintext attack, and its basic concept is to study the probability of differential propagation of definite plaintext differential values in the encryption procedure.

It can separate the block cipher from the permutation area and then produce the key recovery attack on this basis. In another term, it can find a high probability differential trail.

Finally, by inserting multiple rounds before and after the differential characteristic, guessing Round-keys used in these rounds, encrypting plaintexts, and decrypting ciphertexts, and it can decide the right key of block cipher.

Mixed-integer linear programming is a scientific optimization or feasibility design, where some or all variables are defined to integers. In some cases, it can define an integer linear program (ILP), which is linear in terms of objective function and constraint except for the integer constraint. MILP is generally used in business and finance to solve issues of optimization.