What is SHA-256 Hash?
SHA-256 is a cryptographic hash function that converts any file — a video, PDF or database — into a fixed 64-character fingerprint. The same file always produces the same fingerprint, while changing even a single bit produces a completely different one, and it is computationally infeasible to craft a second file matching a given fingerprint. It is a one-way process: the hash cannot be reversed into the file.
This makes SHA-256 the standard integrity seal for digital evidence: hash a CCTV export the moment it is collected, note the value in the seizure record, and anyone can later re-hash the file to prove it is untouched — a mismatch means tampering or corruption. The same function underpins password storage, download verification and blockchain. Computing a hash is free and takes seconds with built-in OS tools.