A Secure Three-Tier On-Chain NFT Framework for Transparent Double-Counting-Resilient Carbon Emission Accounting

Double counting in supply-chain carbon accounting can arise when an emission-related claim remains usable after splitting or integration. Existing systems can strengthen traceability, evidence integrity, or ex-post auditing without defining whether a consumed claim remains valid for reuse. We model this gap as a lifecycle-state consistency problem and present a three-tier framework compatible with Ethereum Request for Comments 1155 (ERC-1155), with three non-fungible token (NFT) lifecycle roles: parent NFT (P-NFT), child NFT (C-NFT), and integrated NFT (I-NFT). The execution-time control layer enforces quantity conservation, immediate parent retirement, and complete-set same-transaction consumption, rejecting violations before state commitment. I-NFT verification binds each integrated claim to its consumed input set through a compact header and issuance-transaction events. Functional validation shows that quantity inflation, parent reuse, partial integration, and consumed-child reuse revert with unchanged checked post-state, while a valid lifecycle passes consistency checks. Gas evaluation over n∈{1,3,6,9,12,50,100} shows near-linear growth: Split at n=50 uses 12.91 M gas, while n=100 uses 25.75 M and exceeds the current 16.78 M Ethereum transaction cap. Blockchain and ERC-1155 are deployment and representation choices rather than correctness mechanisms. The security claim is limited to on-chain lifecycle consistency; physical-world input authenticity remains external.