How Can Anyone Verify a Proof of Existence?
After timestamping a document, keep the exact file and its proof references. A reviewer can calculate its SHA-256 fingerprint, compare it with the registered value and inspect the blockchain record. A match supports existence of that version by the recorded time; it does not establish who created it.
This is where a lot of people get stuck. They understand the idea of blockchain timestamping in theory, but the verification step feels like a black box. It isn't. It's actually one of the simplest parts of the whole process, and understanding it is what turns a proof of existence from an abstract concept into evidence you can rely on.
The Short Version: It's About Math, Not Trust
A blockchain timestamp provides an independently inspectable reference for a file fingerprint. Verification compares the exact file with that reference. This is evidence of prior existence and integrity of that version, not proof of authorship, ownership or identity.
When a file is timestamped through Certelo, the platform doesn't upload or store your actual document. It generates a SHA-256 fingerprint in the browser and registers it with blockchain evidence. The original is not uploaded. Anyone can inspect the public blockchain reference, but checking that it corresponds to a particular file requires calculating that file’s fingerprint.
What Verification Actually Looks Like
In practice, verifying a proof of existence involves three basic checks, and none of them require specialized technical knowledge:
Re-hash the document. A reviewer calculates the SHA-256 fingerprint of the preserved file. A different fingerprint means it does not match the registered version; it does not explain why the difference occurred.
Compare it to the blockchain record. Compare the calculated fingerprint with the registered value. A match supports that this exact file version existed by the recorded time. Only the fingerprint was submitted to Certelo, not the original document.
Check the timestamp against the ledger. Inspect the transaction and its confirmation on the blockchain. Use the recorded time as a reference; it is not the file’s exact creation time and does not guarantee legal acceptance or an outcome.
The blockchain reference can be inspected independently of Certelo’s website. Preserve the original file, certificate and usable transaction references so a reviewer can make the comparison. Access to the relevant blockchain data and verification tools is still needed.
Why This Matters for Legal and Compliance Use Cases
For anyone dealing with intellectual property, this distinction is significant. If a copyright infringement claim is being assessed, a matching fingerprint and blockchain reference can contribute evidence of a saved file’s prior existence. They do not establish authorship, copying or infringement, and do not determine how a court will weigh the evidence.
The same comparison can help review saved business documents, reports or contract versions. Keep the records that explain their contents, authors, approvals and delivery. Timestamping does not establish compliance, accuracy or the events described in a document.
Timestamping also applies to AI-generated content, but cannot distinguish it from human-made work. Provenance systems such as C2PA address separate provenance questions. A timestamp alone does not identify a creator, authenticate a depicted event or demonstrate compliance with AI regulation.
Verification Without the Guesswork
A reviewer with the exact file and proof references can calculate the fingerprint and inspect the blockchain record without relying solely on Certelo’s account of it. They must still assess identity, custody and context separately.
Keep the original file and certificate together. The fingerprint comparison can check a particular saved version against a recorded time reference; it does not reconstruct the complete history of the file.