MD5

File Format
Name	MD5
Ontology	Electronic File Formats Encryption MD5
PRONOM	fmt/993
Released	1991

MD5 is a widely used 128-bit cryptographic hash function.

Specifications

• RFC 1321

Software

• OpenSSL (openssl dgst -md5)
• GNU coreutils → md5sum

Links

• Wikipedia article
• Is “double hashing” a password less secure than just hashing it once?