Confidentiality-minded framework for blockchain-based BIM design collaboration

Building Information Modeling (BIM) is widely adopted for design collaboration in the architecture, engineering, and construction (AEC) industry, while its centralized paradigm suffers the risk of data manipulation. To this end, blockchain is an emerging distributive technology that guarantees data authenticity and integrity by providing decentralized, immutable, and traceable data storage. However, directly integrating BIM with blockchain risks leaking sensitive data, since a blockchain is a transparent network insofar as shared information (including sensitive data) can be disclosed to all members without access control. Therefore, this paper proposes a confidentiality-minded framework (CMF) for blockchain-based design collaboration. The major innovations are twofold. First, an access control model is developed in the CMF to prevent unauthorized access to sensitive BIM data in a blockchain ledger. Second, new design strategies are developed in CMF to facilitate design coordination within the access-controlled blockchain network. An illustrative design example validates the feasibility and performance of the proposed CMF, which has acceptable latency and storage cost. The results also show that the sensitive BIM data are effectively kept confidential when project members collaborate within the CMF.