How it works

Protocol architecture, data model, and federation mechanics for technical audiences.

Protocol overview

Landblock is built on Polygon PoS (EVM-compatible, chainId 137 mainnet / 80002 Amoy testnet). Smart contracts are written in Solidity using OpenZeppelin and compiled with Foundry. Off-chain evidence is stored on IPFS and Filecoin. Identity uses SpruceID DIDs with zero-knowledge selective disclosure proofs.

Mirror Mode

Mirror Mode is the foundational operating model. A registry publishes signed proofs of its records to the Landblock federation, anchored on Polygon with off-chain evidence stored on IPFS/Filecoin. Landblock stores these as immutable metadata — a mirror of the registry's authoritative state. The registry retains full control over underlying data and disclosure policy.

Conformance tiers

• Mirror. Publishes cryptographic proofs. External parties can verify proofs. Registry retains full data control.
• Verified. Passes conformance review. Participates in federated verification routing.
• Full Federation. Direct federation relationships with other registries, shared evidence exchange, dispute interoperability.

Bitemporal records

Every record in Landblock carries three time dimensions:

• Valid time — when the fact was true in the real world (registry-asserted): validTimeStart / validTimeEnd
• System time — the exact UTC moment Landblock recorded the event (Landblock-set)
• Block timestamp — Polygon validator timestamp (automatic)

Records also carry registryRecordedAt (timestamp from the source registry) and supersedes (reference to prior record for corrections). Storage is append-only — no record deletions.

Trust Context

Cross-registry verification results include a Trust Context:

• DIRECT_FEDERATION — registries have a direct federation relationship
• SHARED_ACCREDITOR — both accredited by the same authority
• THIRD_PARTY_ATTESTATION — trusted third party attested to the record
• NONE — record published but no trust relationship exists

Federation Liaison Service

Cross-registry queries are routed through a three-tier Federation Liaison Service:

• Tier 1 — Automated — AI-automated routing for standard queries
• Tier 2 — Facilitated — registry-to-registry channel for complex queries
• Tier 3 — Escalated — human operators for edge cases and disputes

Tiered disclosure

Registries control access to their records through three disclosure levels:

• Public — accessible to anyone
• Restricted — accessible to accredited institutions
• Sealed — accessible only under court order or registry authority

Security

• OpenZeppelin AccessControl with granular role-based permissions
• Pausable functionality for emergency stops on all registry contracts
• Replay protection via nonce-based hash reconstruction (ADR-0018)
• Daily relayer cap (100 spatial unit registrations per day)
• 72-hour challenge window for spatial unit registrations
• 3-of-5 threshold signatures for spatial unit ingest