  Maintaining accurate provenance records is paramount in digital forensics, as
they underpin evidence credibility and integrity, addressing essential aspects
like accountability and reproducibility. Blockchains have several properties
that can address these requirements. Previous systems utilized public
blockchains, i.e., treated blockchain as a black box, and benefiting from the
immutability property. However, the blockchain was accessible to everyone,
giving rise to security concerns and moreover, efficient extraction of
provenance faces challenges due to the enormous scale and complexity of digital
data. This necessitates a tailored blockchain design for digital forensics. Our
solution, Forensiblock has a novel design that automates investigation steps,
ensures secure data access, traces data origins, preserves records, and
expedites provenance extraction. Forensiblock incorporates Role-Based Access
Control with Staged Authorization (RBAC-SA) and a distributed Merkle root for
case tracking. These features support authorized resource access with an
efficient retrieval of provenance records. Particularly, comparing two methods
for extracting provenance records off chain storage retrieval with Merkle root
verification and a brute-force search the offchain method is significantly
better, especially as the blockchain size and number of cases increase. We also
found that our distributed Merkle root creation slightly increases smart
contract processing time but significantly improves history access. Overall, we
show that Forensiblock offers secure, efficient, and reliable handling of
digital forensic data
