Auditing provides an essential security control in computer systems, by\nkeeping track of all access attempts, including both legitimate and illegal\naccess attempts. This phase can be useful to the context of audits, where\neventual misbehaving parties can be held accountable. Blockchain technology can\nprovide trusted auditability required for access control systems. In this\npaper, we propose a distributed \\ac{ABAC} system based on blockchain to provide\ntrusted auditing of access attempts. Besides auditability, our system presents\na level of transparency that both access requestors and resource owners can\nbenefit from it. We present a system architecture with an implementation based\non Hyperledger Fabric, achieving high efficiency and low computational\noverhead. The proposed solution is validated through a use case of independent\ndigital libraries. Detailed performance analysis of our implementation is\npresented, taking into account different consensus mechanisms and databases.\nThe experimental evaluation shows that our presented system can process 5,000\naccess control requests with the send rate of 200 per second and a latency of\n0.3 seconds.\n