Category · tier-1 reading. This page is one implementation of H33's chain-agnostic integrity thesis. For the concept that spans all 11 supported chains, see Public Integrity Layer.
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 Ethereum. It expresses the H33-74 primitive for the Ethereum anchor surface; it does not add a new capability.
What you are reading. "H33-74 evidence anchored on Ethereum" is the H33-74 primitive — the portable 74-byte post-quantum proof produced and owned by H33-74 — expressed on Ethereum as its anchoring substrate. H33-74 is the proof primitive. Ethereum 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 Ethereum transaction that commits to a receipt's cryptographic identity (or to a batched commitment covering many receipts). The anchor lives in Ethereum's canonical ledger and is independently verifiable via any Ethereum block explorer.
H33-74 anchors to Ethereum via EIP-1559 transactions whose calldata contains the receipt's 32-byte commitment (or a Merkle root over a batch). The anchoring transaction is a self-send (no value transfer) with the commitment embedded in calldata so any Ethereum node can index and verify it.
What it does not contain: sensitive payload data. The receipt's content lives off-chain. The anchor only commits to its existence and identity.
Ethereum is the right anchor for receipts that need to interoperate with other Ethereum-based attestation infrastructure (EAS, Verax, Sign Protocol) without depending on them, when the operator's ecosystem is already Ethereum-native, and when calldata-based commitment is preferable to opcode-based commitment (OP_RETURN-style). Ethereum's finality is fast and settlement assurance is high.
A receipt anchored on Ethereum 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 Ethereum 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 Ethereum.
A third-party verifier needs the H33-74 receipt, the Ethereum 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.
Ethereum is not always the right anchor. Another chain may be a better fit when per-anchor cost must stay low at high volume (mainnet gas can be significant), when sub-second or sub-minute finality is required, or when you want the longest-horizon settlement assurance regardless of ecosystem. Those are legitimate reasons to anchor on Solana for throughput and cost, Polygon or Arbitrum for EVM-compatible L2 economics, Avalanche for fast finality, or Bitcoin for maximal settlement assurance 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 Ethereum can anchor to any of the others.
One Receipt. Multiple Chains. H33-74 Overview