Forensic cloning of hard drives and storage devices

In any legal proceeding, it is essential that digital evidence stored on storage devices remains intact from the moment it is acquired. This ensures its authenticity can be verified at any later stage of the process. If this principle is not followed, the evidence may be challenged or rendered inadmissible. Therefore, the digital forensic expert is responsible for maintaining and certifying the chain of custody of the digital evidence obtained.

The recognized methods for preserving such integrity are forensic cloning and forensic imaging. Although both involve a bit-by-bit copy of the original device, cloning writes directly to another physical medium, while forensic imaging stores the copy as a file, allowing analysis without altering the original.

Both procedures involve copying the entire contents of a storage device exactly, bit by bit, either to another physical medium or to a forensic image file. During the process, a hash value is calculated from the data, which allows verification of a perfect match between the original and the copy or image. A hash is a unique alphanumeric string generated from the content. If even a single bit differs, the hash values will not match, indicating the evidence has been altered.

The forensic expert must thoroughly document the entire acquisition process, whether using cloning or imaging, including the type and condition of the original device, the specifications of the destination medium or image format, and the calculated hash values. All this information must be clearly included in the forensic report to demonstrate that the integrity of the evidence has been preserved.

Forensic acquisition requires a properly equipped environment, with specialized hardware and certified software capable of performing a bit-by-bit copy without risk of alteration. Improper handling can contaminate the evidence: for example, connecting a drive without a write blocker may cause system changes that legally invalidate the evidence.

At FORENSICTECH, we operate a mobile forensic lab to perform on-site forensic interventions, including at judicial facilities. Our firm uses a professional Image MASSter Solo-4 Forensic duplicator, capable of performing forensic copies of hard drives and USB devices using both cloning and forensic imaging modes, automatically generating a report with the hash values to ensure full traceability and evidential validity of the process.