LPsLux Proposals
Post-Quantum Cryptography
LP-4830

P3Q-zchain Circuits

Draft

Z-Chain circuit library compiled to the P3Q STARK substrate — encrypted-state proofs, privacy-pool circuits, confidential-transfer circuits, and FHE-bootstrap-key-validity circuits.

Category
Core
Created
2026-05-18

Abstract

P3Q-zchain is the Z-Chain (LP-8000) circuit library compiled to the P3Q STARK substrate (LP-4800). It replaces the BN254-pairing SNARK verifier inherited from the upstream Plonk lineage with a strict-PQ STARK verifier so that Z-Chain's encrypted-execution layer (LP-8045) provides end-to-end post-quantum security with no classical fallback at the proving layer. This LP enumerates the mandatory circuit set: (a) encrypted-state transition proofs, (b) privacy-pool deposit / withdraw proofs, (c) confidential ERC-20 transfer proofs, (d) FHE evaluation-key validity proofs feeding F-Chain (LP-7200), and (e) Z-Chain ↔ F-Chain message-format attestations. Each circuit's AIR layout, public-input encoding, and verifier-side gas cost will be specified per-circuit in sub-LPs once the P3Q parameter set is finalized.

Reference implementation

  • Primitive: luxfi/zchain/circuits (P3Q backend, planned)
  • STARK substrate: LP-4800-4820
  • Z-Chain home: LP-8000
  • Encrypted execution interface: LP-8045

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