OpenTimestamps Bitcoin anchor

What it is

OpenTimestamps (OTS) is an open protocol that submits a hash to OTS calendar servers, which aggregate hashes and commit the aggregate to a Bitcoin transaction. The resulting .ots proof file ties the original hash to a specific Bitcoin block.

Once the proof exists, the hashed content cannot have been retroactively created past the anchored block — doing so would require rewriting Bitcoin's history. Promethean anchors workspace chain heads at tier-dependent cadence: daily (Dev/Team), hourly (Production), 30-min (Scale), real-time (Enterprise).

The proof verifies offline against any Bitcoin full node. Regulators don't need to trust Promethean to verify the anchor — they need Bitcoin's chain. This is the structural answer to 'how do we know the chain wasn't constructed after the fact?'.

What it guarantees

• Third-party-verifiable upper bound on when the chain head existed.
• Independent of Promethean infrastructure — survives Promethean disappearing.
• Cryptographic, not legal — no contract or trust assumption.
• Free at the protocol layer — calendar servers absorb the cost; Promethean adds operational reliability.

What it does NOT guarantee

Honest limits. Every primitive has them.

• That the chain head represents valid entries — it's a timestamp, not a content check.
• Real-time anchoring at sub-block latency — Bitcoin's block cadence is ~10 minutes; anchoring is bounded by that.
• Resistance against Bitcoin chain rewrites — practically impossible for deep blocks, but theoretically not impossible.

Regulations that engage this kind

Sectors that rely on this kind

• Fintech
• Healthtech
• Energy
• Govtech

Related evidence kinds

FAQ