What is OpenTimestamps? Bitcoin Anchoring for Digital Media Provenance
Definition: OpenTimestamps is a protocol that aggregates cryptographic hashes into a Merkle tree and commits the root to a Bitcoin transaction, creating an independently verifiable time attestation that survives any company's failure.
TL;DR: Anchoring answers "when did this exist?" with math, not trust. A Merkle root over a day's manifests goes into a Bitcoin transaction, and anyone can run ots verify against the public block forever. No token, no account, no dependency on the company that signed.
Why a timestamp is the third layer
A signature says who. A watermark survives the asset's worst day. Neither proves when independently of the signer. OpenTimestamps does: it places a commitment in a Bitcoin block, and the block header is a public fact. Even if Original Pictures goes dark, the proof in the block still verifies.
How aggregation keeps it cheap
Anchoring every file on-chain would be slow and expensive. Instead, thousands of daily manifest hashes are folded into one Merkle tree and only the root is committed. The per-signature cost falls below a millionth of a cent at ten million signatures a day. Each file keeps a small proof that walks from its hash up to the anchored root.
Verifying without us
The proof file plus a Bitcoin block explorer is all anyone needs. ots verify proof.ots confirms the commitment against the chain. This is the property courts and newsrooms care about: the verification path has no vendor in it. Peter Todd's protocol has run since 2012, which is most of the point, it is boring, public infrastructure.
The incident behind this
Arup lost about US$25.6 million to a deepfake CFO video call in January 2024. If the executive's authentic communications had been signed and anchored, the absence of a valid proof on the fake would have been a fast, independent tell rather than a trust judgment under pressure.
Implementation
# Verify a timestamp proof against Bitcoin, no API key ots verify manifest.ots # Success: Bitcoin block 880123 attests existence as of 2026-05-20
FAQ
Do I need to buy cryptocurrency?
No. There is no token. Anchoring is a commitment in a public chain; you verify with a free command and a public block explorer.
Why Bitcoin and not a private chain?
A private chain reintroduces a trusted party. Bitcoin's block headers are public and adversarially maintained, which is what makes the timestamp independent of any single company.
Where Original Pictures stands today
Original Pictures ships three things today: a Sign API, a Verify API, and the SDKs that wrap them. One POST /v1/sign attaches a C2PA-format manifest, an invisible TrustMark watermark, and an OpenTimestamps anchor. The open-source verifier checks any of it without calling us.
Two things are on the near roadmap, and we name them as roadmap, not as shipped: C2PA Conformance Program recognition (target Q3 2026, until then our manifests use the published C2PA v2.2 format and any C2PA-aware validator can read them, but third-party validators will show our signer as not-yet-listed), and a consumer capture app (Q3 2026). We do not sell a capture SDK, and we do not claim Trust-List membership we do not yet hold.
Bottom line: OpenTimestamps anchoring is the layer that outlives the company. Commit a daily Merkle root to Bitcoin and any party can prove when content existed with one command, forever.
Related
Original Pictures is progressing through the C2PA Conformance Program; our signing certificate is not yet on the official C2PA Trust List. Target: Q3 2026. We will not describe ourselves as "C2PA-certified" until it is true.
Original Pictures provides content-provenance infrastructure. It does not by itself constitute legal compliance with the EU AI Act or any other regime; compliance depends on how you deploy it, your disclosures, and your governance. Figures are drawn from public reporting, verify against primary sources before citing in regulated materials. Nothing here is legal advice.
Last verified 2026-05-25. Author: Mahdi Kazempour, Founder, Original Pictures.