ZAP1 Attestation Protocol

ZAP1 is an open-source attestation protocol for Zcash. It writes structured lifecycle events to a BLAKE2b Merkle tree and anchors the tree root on-chain via Orchard shielded memos. Proofs are publicly verifiable. Event data stays private.

How it works

Operators register event types (deployments, payments, transfers, etc.) and submit them to a ZAP1 instance. Each event produces a leaf hash using domain-separated BLAKE2b-256. Leaves accumulate in a Merkle tree. When a threshold is reached, the tree root is encoded as a ZAP1:09 memo and anchored to Zcash in a shielded transaction.

Anyone with a leaf hash can verify the full path from leaf to root to on-chain anchor, without trusting the operator.

Key properties

• Application-agnostic: any Zcash operator can define their own event types and personalization strings
• Privacy-preserving: event payloads are hashed before anchoring. Only hashes go on-chain.
• Independently verifiable: verification needs only the proof bundle and chain access. No operator trust required.
• ZIP 302 compatible: ZAP1 is converging toward a ZIP 302 partType for the attestation payload

What exists

• Reference implementation (Rust, MIT licensed)
• Verification SDK on crates.io (Rust + 83KB WASM)
• JavaScript SDK on npm
• Universal memo decoder (identifies ZAP1, ZIP 302 TVLV, text, binary, and empty memos)
• Conformance kit with 29 API checks and 14 protocol checks
• FROST 2-of-3 threshold signing design for multi-party anchor broadcasting
• ZIP draft PR #1243 under review
• 4 mainnet anchors with 14 leaves as of March 2026

Architecture

Your app  -->  ZAP1 API  -->  Merkle tree  -->  Zcash anchor
                  |                                    |
             event types                         shielded memo
          (DEPLOYMENT, etc)                    (ZAP1:09:{root})