Access control has become problematic in several organizations because of the difficulty in establishing security and preventing malicious users from mimicking roles. Moreover, there is no flexibility among users in the participation in their roles, and even controlling them. Several role-based access control (RBAC) mechanisms have been proposed to alleviate these problems, but the security has not been fully realized. In this work, however, we present an RBAC model based on blockchain technology to enhance user authentication before knowledge is accessed and utilized in a knowledge management system (KMS). Our blockchain-based system model and the smart contract ensure that transparency and knowledge resource immutability are achieved. We also present smart contract algorithms and discussions about the model. As an essential part of RBAC model applied to KMS environment, trust is ensured in the network. Evaluation results show that our system is efficient.Information 2020, 11, 111 2 of 15 stored-in files to complex, heterogeneous array of systems with sophisticated options, there are several components of a KMS, and these KMSs deploy KM portals as central points of access for its component systems.The role-based access control (RBAC) framework has been the mechanism employed by most KMSs to achieve access control [4,5]. With roles and titles or statuses, instead of users attributed to access rights, many of today's organizations adopt such a model to implement their access control mechanisms [6][7][8][9][10]. With this contention in the existing literature, both researchers and practitioners over the years continued to extend the core RBAC to include features that: (1) protect and wholly secure knowledge assets; (2) align with KM initiatives; and (3) maintain the determination and motivation to share and transfer knowledge. It is important to emphasize that KM initiatives embrace numerous socio-technical elements, processes, structures, and business models in a broader spectrum. Social entities such as individuals, projects teams, collaborative groups, and inter-organizational relationships use sophisticated technological tools to function in organizations. The dynamics associated with systems and human interactions in KMS environment require critical security attention as users generate, store and utilize knowledge assets. A challenge to such KMS strategic initiatives is thus contingent on the appropriateness of the extension of RBAC deployable in KMS without compromising the overall knowledge sharing or transfer agenda.As with other information systems, users of KMS occupy roles through specific portals and platforms, and these roles are associated with permissions. At different access levels, users can access knowledge items (or objects) and perform operations on them according to their defined specific tasks. With roles associated with a set of sessions, users are allowed to share or transfer knowledge packages across different hierarchical levels. Since knowledge gives organizations competitive advantage [1...