MD5

MD5 (Message Digest 5) is a 128-bit cryptographic hash function published by Ron Rivest in 1992. Practical collisions were demonstrated in 2004, and chosen-prefix collisions have been used to forge TLS certificates (the Flame malware, 2012). MD5 is unsafe for digital signatures, password hashing, and certificate fingerprinting, but remains acceptable as a non-cryptographic checksum (file integrity against accidental corruption, ETag generation, cache keying). Migrate any security-sensitive MD5 usage to SHA-256 or a dedicated KDF like Argon2.