Keychain Signet: A Notarised Asset Ledger with BFT Consensus and Per-Key Hash Chains

Abstract

Asset ownership tracking is fundamental to economic activity, yet it remains fragmented across paper-based deeds, centralised registries, and siloed databases. Public blockchains provide immutability but suffer from scalability limitations and inflexible consensus mechanisms unsuitable for enterprise deployment. We present Keychain Signet (KCS), a decentralised architecture designed as a notarised asset ledger that strictly separates application logic, consensus, and persistence. KCS distributes responsibilities: service providers manage application workflows, notaries enforce validity and uniqueness via BLS signatures, and storage nodes execute BFT-Raft consensus to order blocks. This architecture enforces a "notarised append" model where authorised writes are persisted and ordered by the storage cluster. Unlike standard blockchains, our architecture resolves the latest asset state in O(1) time via a disc-backed Distributed Hash Table while maintaining an immutable, cryptographically linked history for auditability. Experimental evaluation demonstrates 401.1 TPS throughput, notary signing latency of 1.6–10.2 ms scaling linearly with committee size, signature verification under 0.81 ms, and storage persistence under 700μs. The system tolerates Byzantine faults, storage corruption, and node crashes while preserving safety and liveness guarantees.