BitProof

BitProof lets you verify 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 record 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.

EXIF metadata can be edited or removed without changing the visible image. BitProof timestamps the entire file bytes by SHA-256 hash and anchors that hash to Bitcoin through OpenTimestamps. That proves the exact file existed by the anchored time and detects any later modification.

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.

BitProof can optionally verify an authorship signature if one was included when the proof was created. This confirms control of a signing key for that content hash. It does not prove legal identity by itself. For stronger authorship claims, combine signatures with external identity evidence.

Not by itself. BitProof proves the file existed by the anchored time and stayed unaltered since. It does not independently prove camera ownership, location, or that the capture moment matches an EXIF timestamp. For stronger claims, combine BitProof with corroborating evidence.

Yes. On Timestamp File, tap Use Camera / Photo, select or capture an image, and BitProof hashes it in-browser before creating the timestamp proof. For URL archiving from mobile share flows, see Archive Web.

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.