A widely used cryptographic hash function that can generate a 128 bit (16 byte) hash value to ensure complete and consistent information transmission. MD5 was designed by American cryptographer Ronald Linn Rivest and was publicly released in 1992 to replace the MD4 algorithm. The program for this algorithm is standardized in the RFC 1321 standard. After 1996, it was confirmed that the algorithm had weaknesses and could be cracked. For data that requires high security, experts generally recommend using other algorithms such as SHA-2. In 2004, it was confirmed that the MD5 algorithm cannot prevent collisions and is therefore not suitable for security authentication purposes such as SSL public key authentication or digital signatures