Why are cryptographic hashes used when creating a forensic image?

• A. To verify integrity and detect any alteration of the copy.
• B. To compress the data for storage.
• C. To encrypt the image for transfer.
• D. To speed up the imaging process.

Answer: (A)

Cryptographic hashes act as a digital fingerprint for data. When you image a system for forensic purposes, you need to prove that the copy you created matches the original exactly and that nothing has changed during capture, transfer, or storage. A hash function outputs a fixed-size digest from the entire data; it’s deterministic, so the same data always yields the same hash, and any tiny alteration produces a different digest. By comparing the hash of the original evidence with the hash of the forensic image (and rechecking after transfers), you can verify that the copy is authentic and unchanged, which is crucial for maintaining the integrity and admissibility of evidence.

This isn’t about compressing data, encrypting it for confidentiality, or speeding up the imaging process. Hashing is specifically used to detect alterations and verify integrity, making it the best choice for explaining why cryptographic hashes are used in forensic imaging.