Blockchain-based Security and Access Control for BIM Big Data

We analyzed the limitation in traditional role-based only access-control mechanism. As the number of mobile users is much larger than the number of roles, naive RBAC may not be suitable in BIM situations. We thus propose a context-aware fine-grained access control, called CaAC. We describe the functions of CaAC by formal method and present several illustrations on contexts via location-CaAC and the time-aware access control. CaAC can guarantee the access control within the same role by differentiating contexts, which is more fine-grained than current role-based only access control. We also present grouping algorithms of two models. By comparing the proposed models with traditional RBAC model, we analyze the security and feasibility. As a result of analysis, we conclude that the average efficiency is improved by 2n I (2n - p - q), and the time complexity of the proposed algorithm is 0(n).