A Reproducible Blockchain-Anchored Proof-of-Charge Platform for Auditable EV Charging Receipts

Public electric vehicle (EV) charging increasingly relies on internet-connected platforms for metering, billing, roaming, and settlement. However, final billing records and charge detail records often provide limited evidence that a session result can be independently linked to the ordered metering data from which it was derived. This paper presents a reproducible blockchain-anchored Proof-of-Charge platform for generating tamper-evident and auditable EV charging receipts. The platform converts charging-session data into canonical receipts, computes cryptographic commitments over receipt content and ordered meter values, aggregates receipt hashes using a temporally ordered and domain-separated Merkle profile, and anchors compact batch commitments in a smart contract while keeping detailed records off-chain. A working prototype implements cross-language canonicalization checks, membership-proof generation, structured storage, batch anchoring, verification services, synthetic workload generation, dataset export, and local blockchain deployment. Across 50 measured runs covering 10 to 1000 receipts, all count reconciliations, batch-root checks, and on-chain comparisons passed. Mean receipt-pipeline latency ranged from 7.152 to 7.853 ms per receipt, with throughput from 127.54 to 141.23 receipts/s. A focused 1000-leaf proof sample produced a 2064-byte proof with ten sibling hashes. The results show that the platform can generate, anchor, and verify auditable EV charging receipts with reproducible performance while keeping detailed charging data off-chain. The proposed architecture provides a practical digital trust layer for internet-enabled EV charging and V2G-ready settlement workflows.