MD5
Also called: Message Digest 5
Course: AP® Cybersecurity Shows up in: Unit 4: Securing Devices
An older hash function that produces a 128-bit hash. It is deprecated because collisions can be forced efficiently.
Appears in the course and exam description (CED): 4.2.A.14.2.A.4
Why it matters in Unit 4
If an exam scenario stores passwords with MD5 or SHA-1, that is a weakness: both are deprecated hash functions.
Example
Researchers have built two different files with the same MD5 hash, so an MD5 match no longer proves a file is unchanged.
Learn it properly, with a checkpoint 4.2 AuthenticationGo deeper: the professional references
Security professionals worldwide use these: the NIST glossary (the U.S. government's official security dictionary), MITRE ATT&CK (real attacker techniques), MITRE CWE (software weaknesses) and the internet's own standards (RFCs). They go beyond the AP® course, so use the definition above for the exam.