Related · tier-1 reading. For the integrity anchor that makes this verifiable, see Avalanche Evidence Anchoring.
Anyone recording high-stakes operational evidence needs it to outlive the system that produced it. H33-74 is the primitive that produces and anchors that portable post-quantum evidence — this page shows H33-74 evidence anchored on Bitcoin. It expresses the H33-74 primitive for the Bitcoin anchor surface; it does not add a new capability.
What you are reading. "H33-74 evidence anchored on Bitcoin" is the H33-74 primitive — the portable 74-byte post-quantum proof produced and owned by H33-74 — expressed on Bitcoin as its anchoring substrate. H33-74 is the proof primitive. Bitcoin is one interchangeable anchoring substrate beneath it. The chain notarizes when a commitment existed; it is never the source of the proof or the trust.
Each anchor is a Bitcoin transaction that commits to a receipt's cryptographic identity (or to a batched commitment covering many receipts). The anchor lives in Bitcoin's canonical ledger and is independently verifiable via any Bitcoin block explorer.
H33-74 anchors to Bitcoin primarily via Taproot (BIP-341 P2TR), which provides witness-discounted commitment space and the strongest economic security for long-horizon evidence. OP_RETURN is supported as a fallback for tooling that does not yet handle Taproot.
What it does not contain: sensitive payload data. The receipt's content lives off-chain. The anchor only commits to its existence and identity.
Bitcoin is the right anchor when independent notarization needs to survive the longest possible time horizon, when economic security of the notarization matters more than per-anchor cost, and when audit-grade durability is required for regulatory or institutional use. Bitcoin's settlement assurance is the highest available; it makes the strongest single-chain anchor for evidence that must last decades.
A receipt anchored on Bitcoin can also be anchored on Bitcoin, Ethereum, Solana, Polygon zkEVM, Zcash, or any other chain H33-74 supports. The anchors are independent. Adding more anchors does not change the receipt. Removing one anchor (or having one chain become unavailable) does not invalidate the others.
If Bitcoin ever becomes inappropriate for an operator's use case (regulatory, performance, security, cost), the operator adds an anchor on a different chain and continues operating. The historical evidence does not have to migrate, because it was never bound to Bitcoin.
A third-party verifier needs the H33-74 receipt, the Bitcoin anchor transaction (or its hash), and the open-source H33 verifier. From those inputs:
None of those steps depends on H33's infrastructure. The verifier is open-source and the chain is public.
What differs between blockchains are their operational and integration characteristics. The H33-74 primitive and its cryptographic properties remain unchanged.
Migrating from one blockchain to another changes the anchoring substrate and deployment environment. It does not change the H33-74 primitive, the cryptographic evidence, or the verification model.
Bitcoin is not always the right anchor. Another chain may be a better fit when per-anchor cost must be near-zero at high volume, when near-instant finality matters more than decade-scale settlement assurance, or when your evidence needs to live alongside an existing ecosystem such as an EVM contract system, an L2 rollup, or a high-throughput application chain. Those are legitimate reasons to anchor on Ethereum, Solana, Polygon, Avalanche, or Arbitrum instead. In every case the H33-74 receipt stays portable: the same proof moves to the chain that fits, unchanged.
The same receipts that anchor to Bitcoin can anchor to any of the others.
One Receipt. Multiple Chains. H33-74 Overview