TRACC: A Trusted IoT–Blockchain Architecture for Real-Time Carbon Compliance and Device-Level Emission Accountability

Carbon-compliance systems increasingly rely on Internet of Things (IoT) sensing, yet measurement provenance, policy evaluation, and consequence assignment often remain separated. This paper presents TRACC (Transparent Real-Time Accountability for Carbon Compliance), a trusted IoT–blockchain architecture that links authenticated methane reports to device-indexed liability. The novelty lies in the transaction-level accountability semantics: a device-signed report is authenticated against a registered sensing endpoint, evaluated under the on-chain policy, and, when the threshold is exceeded, converted into non-transferable liability assigned to the ERC-6551 account bound to that endpoint. A four-node Raspberry Pi prototype validated the physical sensing-to-minting path against contracts deployed on the Polygon Amoy testnet. Stage-wise characterization yielded a composed pipeline latency of 6.25 s. A fixed-seed 30-day simulation of 1500 devices was complemented by a controlled offered-load benchmark; across 0.22–1.67 transactions s−1, achieved throughput tracked offered load with 100% first-attempt success and no observed saturation. Liability-minting transactions consumed approximately 290,800 gas. Across 146 scripted adversarial scenarios, no unauthorized state change occurred under internal audit. These results demonstrate the feasibility of authenticated, device-indexed liability assignment under the tested prototype and testnet conditions.