This question aligns with CHFI v11 objectives under Data Acquisition and Duplication , specifically image validation and forensic integrity verification . After acquiring a forensic image, it is a mandatory best practice to verify that the image is an exact bit-for-bit replica of the original evidence source. CHFI v11 stresses that verification protects evidence integrity and supports legal admissibility by proving that no data was altered during acquisition.
The dcfldd tool-an enhanced version of the Unix dd utility-supports forensic features such as hashing, logging, splitting, and image verification . The vf (verify file) parameter in the command dcfldd if=/dev/sda vf=image.dd directly compares the original input device (/dev/sda) with the previously created image file (image.dd). This ensures that both sources match exactly, sector by sector.
Option B performs imaging with hashing but does not verify an existing image against the original drive.
Option C simply creates an image without validation, and Option D uses dd with file splitting, which lacks forensic verification features. Therefore, consistent with CHFI v11 acquisition validation standards, Option A is the correct command to verify the forensic image against the original medium.