A Blockchain-based Carbon Auditing Framework for Construction Material and Product (CMP) Certification
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Abstract
The construction industry has an indispensable role in global carbon reduction as it is one of the largest generators of carbon footprint emissions. Of various emission sources at different stages of the construction life cycle, construction materials and products contribute a considerable proportion, and thus their importance should not be neglected. Although multiple carbon certification or labelling schemes for Construction Materials and Products (CMPs) have been launched to assess their carbon emissions, such efforts and practices still rely heavily on traditional centralized data storage and publishment, which suffer data non-transparency and manipulation problems, making it difficult to identify and track carbon footprints of CMPs. Therefore, this paper proposes a transparent and reliable carbon auditing framework for CMP certification based on blockchain technology, which aims to facilitate the management of carbon footprints ranging from raw material extraction, transportation to plants, and manufacturing. In the proposed framework, a two-level privacy blockchain data model summarizing carbon footprints is first developed under data transparency and privacy concerns. An asymmetric encryption scheme integrating with an online document-sharing system, the InterPlanetary File System (IPFS), is then proposed to secure data storage and access during the carbon auditing process. Besides, smart contracts are developed to interact with the blockchain network, which supports generating immutable distributed ledgers of construction material and product carbon footprints. A prototype using Ethereum, a public blockchain development tool, was deployed and evaluated. The feasibility of the framework is validated through an illustrative example, showing that the blockchain-based framework is a promising solution in auditing and tracking the carbon footprints of CMPs.
