See how it works
From plain document to verifiable proof
Take a look at a real document before and after Checksum proofs it, then see what a financial institution, lender, or HR team sees when they verify it.
1. Start with the original document
Here's an unmodified employment verification letter, exactly as created by the employer.
2. Checksum stamps a proof
The employer proofs the document through Checksum. A cryptographic fingerprint is generated and a verification stamp is embedded directly on the page — the document itself now carries its own proof of authenticity. Employer provides the proofed letter to the employee
3. Anyone can verify it instantly
When a third party receives the proofed document, they can upload it on the verify page. Checksum recomputes the fingerprint and confirms it matches what was signed — no phone calls, no manual review.
Document verified
The document is authentic and unchanged.
File
JohnDoe-employment letter-proofed.pdf
Signed by
jane@aiengineers.com
Organization
AIEngineers
Signed on
9/27/2026, 8:27:22 PM
What if someone edits the document after it's proofed?
See what happens when a field — like a salary figure — is changed after the document was proofed, and what a lender or HR team sees when they try to verify it.
See what happens when a document is tampered