MD4 Hash

Definition

MD4 (Message Digest 4) is a cryptographic hash function developed by Ronald Rivest in 1990. It was designed as an improvement over its predecessor, MD2, and aimed to provide faster computation and better security properties. However, similar to MD2, MD4 is now considered insecure and should not be used for cryptographic purposes.

The goal of MD4, like any hash algorithm, is to take an arbitrary input of data and produce a fixed-size hash value, typically 128 bits (16 bytes) in length. The resulting hash is unique to the input data, meaning that even a small change in the input will result in a significantly different hash value. It should be computationally infeasible to derive the original data from the hash value.

MD4 operates on 32-bit words and processes data in blocks of 512 bits. The algorithm applies a series of bitwise logical operations, modular additions, and logical functions to transform the input data. It involves multiple rounds of operations, including bit shifting, bitwise logical functions (such as AND, OR, and XOR), and modular additions.

However, MD4 is vulnerable to various attacks, including collision attacks and pre-image attacks. Collision attacks aim to find two different inputs that produce the same hash value, while pre-image attacks attempt to find an input that hashes to a specific target hash value. Over the years, significant vulnerabilities have been discovered in MD4, making it unsuitable for secure cryptographic applications.

Due to the security weaknesses in MD4, it is strongly recommended to use more secure hash algorithms, such as SHA-256 or SHA-3, for any new cryptographic implementations. These modern hash functions offer improved security features and resistance against known attacks, ensuring the integrity and confidentiality of data.