How the Bharatiya Sakshya Adhiniyam, 2023 turned a forensic technique into a statutory requirement. Includes a practical guide to checking hashes with GtkHash.
Introduction
A pen drive or a CCTV clip reaches the courtroom as a bare file. It looks the same whether it is genuine or edited. The law therefore needs a way to show that the file produced in court is the same file that was seized or extracted. That way is the hash value.
The Supreme Court has described a hash value as "synonymous with an electronic fingerprint" that gives "a sure way of identifying and verifying digital data". A hash is produced by running a file through an algorithm such as MD5, SHA-1 or SHA-256. Changing even one bit of the file produces a completely different hash.
