ProofStamp via Bitcoin
Create a verifiable timestamp without uploading your file.
Choose a file. ProofStamp checks its fingerprint locally with two independent SHA-256 implementations, then submits only a blinded commitment through OpenTimestamps.
1. Choose and check the file
File checked locally
2. Create the timestamp proof
- File SHA-256
- Manifest commitment
- Independent checks
- Web Crypto SHA-256 + RustCrypto SHA-256
Technical details: Canonical Manifest v1
Only a blinded commitment is sent to three approved OpenTimestamps calendars. Your source file and manifest stay on this device.
Timestamp request accepted
3. Save your proof
- Calendars accepted
- Proof SHA-256
- Target
- Bitcoin via OpenTimestamps
Waiting for Bitcoin is not Bitcoin confirmation. Keep the receipt and .ots proof. They can be checked again later.
Already have a receipt?
Check a saved ProofStamp
Open a saved ProofStamp receipt. The browser checks its internal bindings locally first, then asks only approved calendars for updates and checks any Bitcoin attestation.
Proof checked
Bitcoin status
- Manifest commitment
- Bitcoin block height
- Bitcoin block hash
- Bitcoin block time
- Verification method
- OpenTimestamps + Blockstream raw block header
Browser verification is a convenience check. It verifies the OpenTimestamps Bitcoin attestation against a raw block header fetched through Blockstream. It is not equivalent to independently validating Bitcoin consensus with your own Bitcoin Core node.
Independent verification
The proof does not depend on ProofStamp staying online
Save the standard .ots proof and the ProofStamp receipt. A completed proof can be checked with standard OpenTimestamps tooling and your own Bitcoin Core node.