Adaptive Hybrid Consensus Engine for V2X Blockchain: Real-Time Entropy-Driven Control for High Energy Efficiency and Sub-100 ms Latency

We present an adaptive governance engine for blockchain-enabled Vehicular Ad Hoc Networks (VANETs) that manages latency-energy-coherence trade-offs under rapid topology changes3. We introduce (i) an Ideal Information Cycle as an operational abstraction of information injection and validation and (ii) a modular VANET Engine implemented as a real-time control loop in NS-3.354. The Engine monitors normalized Shannon entropies—informational entropy $S$ over active transactions and spatial entropy $H_{spatial}$ over occupancy bins (both on [0, 1])—and adapts the consensus mode (PoW versus signature/quorum-based modes such as PoS/FBA) together with key rigor parameters via calibrated policy maps5. Governance is cast as a constrained operational objective that trades per-block resource expenditure (radio + cryptography) against a Quality-of-Information (QoI) proxy derived from delay/error tiers, subject to timeliness and ledger-coherence pressure6. Cryptographic cost is explicitly traceable through counted operations, $E_{crypto} = e_h n_{hash} + e_{sig} n_{sig}$, and coherence is tracked via an LCA/LCP-normalized ledger-divergence metric7. We evaluate the framework under urban/highway mobility, scheduled partitions, and bounded adversarial stressors (Sybil identities, Byzantine proposers), using 600 s runs with 30 matched random seeds per configuration and 95% bootstrap confidence intervals8. In high-disorder regimes ($S \ge 0.8$), the Engine reduces total per-block energy (radio + cryptography) by more than 90% relative to a fixed-parameter PoW baseline tuned to the same latency target9. A consensus-first triggering policy further lowers agreement latency and increases throughput compared with broadcast-first baselines10. Under high mobility ($v=30$ m/s) in the emphasized urban setting, the Engine bounds orphaning ($\le 10\%$), keeps finality within sub-150 ms ranges, and reduces average ledger divergence below 0.07 at high spatial disorder11. Scope and security envelope: the main evaluation is limited to $N \le 100$ vehicles under full PHY/MAC fidelity12. PoW targets are intentionally latency-feasible and are not intended to provide cryptocurrency-grade majority-hash security; operational security and mode-transition considerations are discussed explicitly in Section 413.