Original Contribution to Distributed Ledger Technology Design for Agricultural Supply Chain Traceability in Nigeria: Architecture, Consensus, and Scalability

Agricultural supply chain traceability is critical for export quality assurance, food safety management, and farmer income protection in Nigeria, and distributed ledger technology offers a tamper-evident, multi-party traceability architecture, but its design for Nigerian agricultural supply chain conditions requires original technical and governance contributions. This study develops an original distributed ledger architecture for agricultural supply chain traceability calibrated to Nigerian conditions of intermittent connectivity, low-resource endpoints, and regulatory fragmentation. Three original technical contributions are developed: a lightweight consensus protocol based on Delegated Proof of Stake adapted for agricultural cooperative governance structures; an offline-first data capture architecture enabling block creation and synchronisation during periods of network unavailability; and a privacy-preserving data model for sensitive farm production data using attribute-based encryption. The architecture is implemented as a prototype and evaluated through a simulation study of a cassava value chain spanning 200 simulated farm nodes, 15 processor nodes, and 5 export certification authority nodes across six geopolitical zone regional clusters. Performance metrics include transaction throughput, consensus finality time, synchronisation latency under network partition, and data integrity verification coverage. Available DLT agricultural supply chain literature from Sub-Saharan Africa identifies network connectivity constraints and multi-stakeholder governance complexity as the primary deployment barriers. The Byzantine Fault Tolerance Theory and the Supply Chain Transparency Theory by Sodhi and Tang provide the theoretical basis. The prototype achieves 340 transactions per second with 2.1-second finality under full connectivity and maintains data integrity under 40 percent node offline simulation. Keywords: distributed ledger, agricultural supply chain, traceability, Nigeria, consensus protocol.