CompTIA SecurityX (CAS-005)Security ArchitectureMedium
A financial institution is designing a new payment processing system that must comply with strict regulatory requirements for data integrity and non-repudiation of transactions. Each transaction must be verifiably linked to the originating party and prove that it has not been altered since it was created. Which cryptographic technique is essential for meeting these requirements?
- ASymmetric encryption
- BHashing with a salt
- CDigital Signatures
- DHomomorphic encryption
Show answer & explanationAnswer & explanation
Correct answer: C. Digital Signatures
Digital signatures provide data integrity (proof of no alteration) and non-repudiation (verifiable link to the originator) by using asymmetric cryptography to sign a hash of the data with the sender's private key.
Why the other options are wrong
- A. Symmetric encryption provides confidentiality but not integrity or non-repudiation.
- B. Hashing with a salt is used for password storage and data integrity checks, but does not provide non-repudiation (linking to an originator) on its own.
- D. Homomorphic encryption allows computations on encrypted data but does not directly address integrity or non-repudiation for transactions.
Digital Signatures
A cryptographic technique used to verify the authenticity and integrity of digital messages or documents, providing assurance of the sender's identity (non-repudiation) and proof that the data has not been altered in transit.
- Uses asymmetric cryptography (private key to sign, public key to verify).
- Provides data integrity and non-repudiation.
- Often involves hashing the message before signing.
Memory trick: Digital Signatures: 'Sign, Verify, Never Deny' your transactions.