Glossary · Security Controls
Also known as: Message Authentication Code
Message Authentication Code (MAC): Short cryptographic tag that proves a message's origin and integrity to a receiver sharing a key. A MAC is computed over a message and a secret key (e.g. AES-CMAC, HMAC).
Where this matters: AUTOSAR Development — Crypto Stack, SecOC and HSM integration
A receiver with the same key can verify both that the message was produced by an authorised sender and that it has not been altered in transit. It underpins SecOC and most automotive secure-communication primitives.
Why it matters
The MAC is the cryptographic primitive that makes message authentication — and therefore SecOC — possible. Getting the algorithm, key length, and freshness handling right is a recurring TARA decision, because weak or missing message authentication is one of the most common findings in automotive threat analysis.
Related terms
Secure Onboard Communication (SecOC) is the AUTOSAR mechanism that adds message authentication and freshness protection to in-vehicle network traffic.
AUTOSAR module that exposes cryptographic services to upper layers.
Lifecycle of cryptographic keys from generation through deployment, rotation, and revocation.
Need help applying Message Authentication Code (MAC) on a programme? Use the contact form to reach Agnile’s engineering team.