Empirical Evaluation of Blockchain Consensus Mechanisms for National Identity Management in Nigeria

Nigeria's National Identity Management Commission operates a centralised biometric identity database that is vulnerable to single-point failures, data breaches, and insider manipulation, and distributed blockchain architectures offer theoretical resilience improvements, but empirical evaluation of consensus mechanisms for the specific performance requirements of a national-scale identity system is absent. This study empirically evaluated four blockchain consensus mechanisms (Proof of Authority, Practical Byzantine Fault Tolerance, Tendermint, and Hashgraph) for suitability in Nigeria's national identity management infrastructure. A testbed was constructed using Hyperledger Besu nodes deployed on a simulated network representing the geographic distribution of NIMC state offices across all six geopolitical zones. Identity registration (write), verification (read), and update transactions were benchmarked under varying network node counts (10, 36, and 100 nodes) and transaction loads (100, 1,000, and 10,000 TPS). PoA achieved the highest throughput at 4,200 TPS for identity verification reads but provided weaker Byzantine fault tolerance. PBFT throughput reached 1,800 TPS with full Byzantine tolerance, but scaled poorly beyond 50 nodes. Tendermint demonstrated the best balance of throughput (2,900 TPS at 36 nodes), fault tolerance, and scalability, with latency below 1.5 seconds per transaction across all tested conditions. Hashgraph showed superior fairness guarantees but required proprietary licensing incompatible with a public identity system. The study recommends Tendermint-based permissioned blockchain as the candidate architecture for a federated national identity management pilot and engagement with NITDA for technical standards development.

Keywords: blockchain consensus, national identity management, NIMC, Tendermint, distributed ledger