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Quiz Entry - updated: 2026.07.30

Of checksum, hash, MAC, and digital signature — which security properties does each provide?

Each step adds a property: checksum→error detection, hash→+integrity, MAC→+authenticity, signature→+non-repudiation.

Cumulative table: simple checksum gives error detection; hash adds integrity; MAC adds authenticity; digital signature adds non-repudiation, each row filling one more column.

* A cumulative ladder — each technique keeps every property below it and adds exactly one more, from error detection up to non-repudiation. *

Mechanism Error detection Integrity Authenticity Non-repudiation
Simple checksum
Hash value
Message Authentication Code (MAC)
Digital signature

The logic of the ladder:

  • A hash detects any change (not just accidental) — but anyone can recompute it, so it doesn't prove who sent it.
  • A MAC adds a shared secret key → now only someone with the key could have produced it (authenticity) — but both parties share the key, so neither can prove to a third party who created it.
  • A digital signature uses the sender's private key → only they could sign, and anyone can verify with the public key → the sender can't later deny it (non-repudiation).

Tip: Non-repudiation needs asymmetric crypto (a key only the signer holds). A shared secret (MAC) can never give it, because either party could have made the tag.

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From Quiz: ISF / Foundations, Key Terms & Ransomware | Updated: Jul 30, 2026