PoAD‐Lite: A Lightweight, Activity‐Aware Consensus Protocol for Scalable and Energy‐Efficient IoT Blockchains

Abstract

The growth of Internet of Things (IoT) applications requires blockchain consensus mechanisms that are efficient, fair and resilient under constrained and intermittently connected operating conditions. This study presents the Proof‐of‐Activity and Delegation‐Lite (PoAD‐Lite), a lightweight consensus protocol that combines activity‐aware eligibility scoring, verifiable randomness, minimal‐state delegation and quorum‐based finality. A Python‐based simulation evaluated PoAD‐Lite against PoW‐Lite, PoS and PBFT‐Lite in committee‐scale IoT/edge settings with 10–100 validators. In addition to assessing scalability, the revised evaluation examines validator churn and adversarial behaviours, including delayed participation, equivocation, invalid block proposals and delegation concentration. The results show that PoAD‐Lite maintains finality under moderate churn of up to 20% with no observed safety violations or unsafe fork events in the tested scenarios. Under severe 30% churn, the finality success rate declines to 77.8%, indicating liveness degradation, whereas safety is preserved. Adversarial tests similarly show that invalid or conflicting proposals are detected and rejected, although stronger Byzantine participation reduces the progress. These findings demonstrate that PoAD‐Lite provides a promising, safety‐preserving and resource‐conscious consensus approach for committee‐scale IoT/edge blockchain deployments, which is evaluated with up to 100 validators.