|Home » ACP » MD
MDGet the message.
A message digest is a small stream of bytes that can cryptographically (and uniquely) identify a file.
Prior to OS version 10.12, MD produced message digests for MD5, MDC2, RIPEMD-160, SHA, SHA-1, and SHA-256. The legacy MD for 10.6 and earlier offered MD2, MD5, MDC2, RIPEMD-160, SHA, and SHA-1.
Starting with 10.12 and moving forward, MD produces message digests for MD2, MD4, MD5, SHA, SHA224, SHA256, SHA384, and SHA512.
Researchers have broken some of the lesser algorithms and are growing suspicious even 160-bit algorithms may not be collision-free. The NSA are looking for another killer algorithm, but with MD you should be all right.
MD constructs all eight message digests at once, with results directly exportable in plain text to disk, so you won't run a message digest on a file to test its integrity - you'll compare MD files instead.
With all those algorithms working on your behalf, collision risks are more remote than ever.