How it actually works
The Trust Center
Most people don't need to understand hashing to trust PaperTrail — but you can see exactly how it works, right here.
SHA-256 fingerprint
This is the avalanche effect — a single character changes roughly half of the fingerprint. That's why a matching hash is such strong evidence: there is no realistic way to alter a paper and land on the same fingerprint by accident.
What does a fingerprint actually prove?
That a specific file existed, unchanged, at a specific moment in time. Nothing more — it can't reveal what's inside the file, and it can't be reverse-engineered back into the original document.
What does a match NOT prove?
Who leaked it, how it spread, or whether the person who uploaded it did anything wrong. A match is a timestamp fact, not a verdict — that's for an investigation to determine.
Can a fingerprint be faked or reversed?
No. SHA-256 is one-way — there's no known method to construct a different file that produces the same hash, and no way to recover the original file from the hash alone.
Why publish the fingerprint before the exam, not after?
Because timing is the entire point. A hash published before the exam begins is proof the paper existed in that exact form beforehand — publishing it afterward would prove nothing.