Which measure confirms the integrity of forensic copies?

Which measure confirms the integrity of forensic copies?

• A. CRC verification
• B. Hash verification during imaging
• C. Use of a write-blocker during imaging
• D. Compute and verify cryptographic hashes of the source and the image

Answer: (D)

Ensuring forensic copies are exactly the same as the originals relies on cryptographic hashes to prove that no changes happened during imaging or subsequent handling. A cryptographic hash produces a unique fingerprint for a file or disk image; even a single bit change would yield a completely different hash. By computing a hash on the source material and then computing a hash on the copied image, and by comparing these two values, you can confirm that the image is an exact replica of the original. This approach is stronger than simple error-checking methods like CRC, which are not designed to resist deliberate tampering and may not detect sophisticated alterations. A write-blocker prevents the original data from being changed during the imaging process, which is important for preserving the source, but it does not verify that the resulting image remains intact over time. Verifying a hash only during imaging might miss changes that occur after imaging, during transport or storage. Therefore, computing and then verifying cryptographic hashes of both the source and the image provides end-to-end integrity assurance, making it the most reliable method for confirming forensic copy integrity.

Ensuring forensic copies are exactly the same as the originals relies on cryptographic hashes to prove that no changes happened during imaging or subsequent handling. A cryptographic hash produces a unique fingerprint for a file or disk image; even a single bit change would yield a completely different hash. By computing a hash on the source material and then computing a hash on the copied image, and by comparing these two values, you can confirm that the image is an exact replica of the original.

This approach is stronger than simple error-checking methods like CRC, which are not designed to resist deliberate tampering and may not detect sophisticated alterations. A write-blocker prevents the original data from being changed during the imaging process, which is important for preserving the source, but it does not verify that the resulting image remains intact over time. Verifying a hash only during imaging might miss changes that occur after imaging, during transport or storage.

Therefore, computing and then verifying cryptographic hashes of both the source and the image provides end-to-end integrity assurance, making it the most reliable method for confirming forensic copy integrity.