Avalanche Evidence Anchoring

Anchor private evidence with a 32-byte post-quantum commitment while keeping the underlying data under customer control.

A complete evidence package can remain private and under customer control while Avalanche serves as the public integrity layer that proves it has not been altered. The 32 bytes on-chain represent the bundle. The bundle stays with the customer. Anyone with the bundle can verify integrity against Avalanche without contacting H33, without phoning home, and without trusting any intermediary.

What gets anchored

The bundle stays private. The chain anchors a 32-byte commitment. Every H33 evidence bundle has a canonical-JSON form. The canonical-JSON digest of the bundle (with the anchor field zeroed, because the anchor cannot reference itself) is exactly 32 bytes. Those 32 bytes are the commitment. The commitment commits to the entire bundle: every evidence control object, every sidecar, every signature, every citation. Changing any byte produces a different 32-byte commitment. The commitment is what goes on-chain. The bundle does not. The underlying data — gigabytes if needed — stays under customer control.

How anchoring works

A self-send transaction on Avalanche C-Chain carries the 32-byte commitment as transaction calldata. The transaction is signed by the bundle owner's wallet — H33 never touches the signing keys. The transaction is broadcast to a public Avalanche RPC endpoint. The Avalanche network confirms the transaction in a block. Once confirmed, the bundle has been anchored. The transaction hash, block hash, and block number are recorded in the bundle's anchor field. The chain serves three roles: time binding (the block timestamp proves the bundle existed at or before that moment), tamper detection (any modification produces a different commitment), and public verifiability (anyone can query the chain to confirm).

The verification path

Any party holding the bundle can verify the anchor. Read the bundle's anchor field. Compute the bundle's 32-byte canonical commitment. Query the Avalanche RPC for the transaction. Confirm it exists in the expected block. Read the transaction calldata. Confirm it matches the computed commitment. Run additional sanity checks: the block hash matches what the chain reports at that height (no reorg); the block contains the transaction; the transaction is finalized. The open-source h33-anchor-verify-inclusion tool performs every check. The verification runs entirely against the public Avalanche RPC. No H33 servers are contacted.

Why Avalanche

Avalanche C-Chain offers properties that matter for institutional evidence anchoring: sub-second finality, EVM compatibility, public auditability, low transaction cost, and subnet flexibility. The H33 anchoring model is chain-agnostic. Avalanche is the current production substrate. Additional chains can be supported without changing the bundle format or verification protocol.

Use cases

AI decision evidence. An AI underwriting system produces an evidence bundle for every decision. The bundle's commitment is anchored to Avalanche. A regulator or auditor verifies any individual decision's anchor without ever seeing the underlying applicant data.

Insurance claim evidence. A cyber insurance claim is supported by H33 evidence bundles. Each bundle's commitment is on Avalanche. The carrier, reinsurer, and regulator each verify the anchors independently.

Healthcare audit trails. A hospital's clinical decision support produces bundles for every recommendation. The bundles are anchored. Years later, in a malpractice case, the original recommendation bundle is verified against Avalanche.

The institutional story

Most workloads anchored to public chains today are trading, tokenization, or payments. Evidence anchoring is different. A 32-byte commitment is the only artifact that touches the chain. The full evidence package — gigabytes if needed — stays under customer control. What gets verified publicly is integrity. What gets retained privately is evidence. That is a new class of institutional workload on Avalanche: verification infrastructure, not transaction infrastructure.

Common questions

Does the chain see the underlying data?
No. Only the 32-byte commitment is published. The bundle stays under customer control.

Can H33 modify a bundle after anchoring?
No. The bundle is signed by three independent post-quantum algorithm families. Modification invalidates the signatures. The commitment also changes, breaking the anchor match.

What if I want to anchor on a different chain?
The H33 anchoring model is chain-agnostic. Adding a chain requires implementing the prepare/broadcast/verify-inclusion path for that chain. The bundle format and verification protocol are unchanged.

Is mainnet supported?
Mainnet anchoring is implemented behind an explicit signing-boundary record. The crate never holds private keys. The customer signs offline; H33 broadcasts the signed transaction; the verifier confirms inclusion. Fuji testnet anchoring is fully shipped and demonstrable today.

Can multiple bundles share an anchor?
Yes. A Merkle root of multiple bundles' commitments can be anchored as a single 32-byte commitment. Each bundle then carries its Merkle path.

Related pages: Portable Artifact · Claims Evidence · Trust Card · Bundles