MD Definition
The MD (Message Digest) family of algorithms are cryptographic hash functions designed to produce a fixed-size hash value from variable-length input data. These algorithms are widely used for ensuring data integrity, creating digital signatures, and other cryptographic applications. The most well-known algorithms in this family are MD2, MD4, and MD5.
Types of MD Algorithms
- MD2: Designed by Ronald Rivest in 1989, MD2 produces a 128-bit hash value. It was optimized for 8-bit machines and is now considered obsolete due to vulnerabilities that allow for collision attacks.
- MD4: Also designed by Ronald Rivest, MD4 was introduced in 1990. It produces a 128-bit hash value and was designed for fast computation on 32-bit machines. However, it has been found to be vulnerable to several types of cryptographic attacks and is no longer considered secure.
- MD5: The most widely known and used algorithm in the MD family, MD5 was designed by Ronald Rivest in 1991. It produces a 128-bit hash value and was widely adopted for various applications, including checksums and digital signatures. However, MD5 is now considered broken and unsuitable for further use due to vulnerabilities that allow for collision and preimage attacks.