Our mission
Important records.
Independently verifiable.
A photo, report or agreement may need to be checked long after it was saved or shared. ProofStamp explores ways to preserve independent evidence of the exact file, so someone can check that version later without relying only on the system that held it.
Keep the original file.
A checkpoint tied to the exact file.
Why it matters · illustrative example
One handover.
Two versions of the report.
You keep a handover report. Months later, someone produces a different copy with the same filename. Which exact version existed at the time?
An independent timestamp obtained at handover gives you a checkpoint. Someone else can check the file against that evidence without relying only on either side’s account.
Example filename, time and results are illustrative.
How it works
Keep the file. Keep the proof.
Email, folders and backups help you keep records. A ProofStamp adds evidence that can help someone check whether a later copy matches the version recorded at a particular checkpoint.
Choose
Select the report, photo or other file that may matter later.
Add a checkpoint
A signed timestamp or public blockchain record adds time evidence tied to the file’s hash.
Keep
Keep the original file and its proof. You will need both for a later check.
Check later
Check that the file matches the recorded hash, then verify the timestamp or public record.
What makes a check independent?
A hash is a value calculated from the exact file bytes. A later check recalculates it and compares the result with the saved proof. The timestamp or blockchain record must also be verified against its source.
Open formats and documented verification methods let others inspect the evidence. Each method has its own dependencies and limits. An email receipt, a signed timestamp and a blockchain record provide different kinds of evidence.
A valid file-and-time check can show that those exact bytes existed no later than the verified time. It does not establish that the contents are true, who created them, when the events happened, or how a dispute should be decided.
From idea to practice
The demos make it tangible.
Try creating a proof and checking it later. Our apps and prototypes demonstrate different methods, from signed timestamps to public blockchain records.
For businesses and builders
Where would a checkable record help?
Consider an inspection report shared at handoff. Months later, a customer or reviewer may want to check whether their copy matches the recorded version. We explore how that kind of proof could become part of existing business workflows.