BitProof

BitProof lets you prove that a file or webpage existed in a specific form at a specific time. It does this by anchoring a cryptographic hash of your content to Bitcoin's blockchain via the OpenTimestamps protocol. The result is a mathematical proof that doesn't require trusting any organization — including us.

No. Your file is hashed entirely in your browser using the Web Crypto API. Only the 64-character SHA-256 hash is sent to our server. We never see, receive, or store your actual file content.

A .bitproof file is a standard ZIP archive containing a JSON manifest (metadata about what was timestamped) and a proof.ots file (the OpenTimestamps cryptographic proof). For web archives, it also includes the captured screenshot, HTML, and PDF. You can open it with any ZIP tool.

Yes. OpenTimestamps is a free protocol — it aggregates many hashes into a single Bitcoin transaction using Merkle trees, so there's no per-timestamp cost. BitProof is currently offered without charge.

Approximately 1-2 hours. OpenTimestamps batches hashes and anchors them to Bitcoin blocks, which are mined roughly every 10 minutes. The aggregation and confirmation process typically takes 1-2 hours total. Your proof is valid as soon as it's created, but it becomes independently verifiable against Bitcoin after confirmation.

Nothing changes. Your .bitproof bundle contains everything needed for independent verification. You can verify it using the standard OpenTimestamps tools (ots verify -d <sha256_hex_digest> proof.ots) without any dependency on BitProof's servers. This allows verification without relying on BitProof infrastructure.

It means the proof has been submitted to OpenTimestamps but hasn't been included in a Bitcoin block yet. Wait 1-2 hours after creating the proof, then verify again. This is normal and expected.

Not currently. BitProof proves existence — that content existed in a specific form at a specific time. Proving authorship would require digital signatures, which is a potential future feature. For now, you can combine a BitProof timestamp with other evidence of authorship.

When you enter a URL, our server loads the page in a headless browser and captures three things: a full-page screenshot (PNG), the complete HTML source, and a PDF rendering. All three are hashed and the combined hash is timestamped to Bitcoin. You get a preview of the capture and a .bitproof bundle containing everything.

Wayback stores historical copies under Internet Archive custody. BitProof adds a cryptographic proof anchored to Bitcoin for the captured content. The proof can be checked independently with OpenTimestamps tools.

No. We capture the page, create the proof, send everything to you, then delete all temporary files. We do not keep a proof database or stored archives. Standard operational logs may exist. If you lose your .bitproof bundle, we cannot recover it.

Verification does not depend on trusting BitProof. Proofs are anchored to Bitcoin and checked with standard OpenTimestamps tooling. BitProof is stateless and does not retain uploaded files or proof records.

The proof guarantees that the SHA-256 hash of your content was included (via a Merkle tree) in a specific Bitcoin block at a specific time. To forge this, an attacker would need to either find a SHA-256 collision (computationally infeasible) or rewrite Bitcoin's blockchain (requires controlling >50% of all mining power on Earth).

Yes. BitProof is open source on GitHub. You can audit the code, run your own instance, or contribute improvements.