SharAcc: Enhancing scalability and security in Attribute-Based Access Control with sharding-based blockchain and full decentralization

Existing Attribute-Based Access Control (ABAC) systems face significant challenges, primarily due to their reliance on a single attribute management authority, which raises concerns regarding reliability and security. To address these issues, this paper presents SharAcc, an innovative sharded blockchain-based access control system that decentralizes attribute management and access control processes. By leveraging sharding technology, SharAcc distributes attribute management and access control processes across multiple shards, significantly boosting system efficiency and security. The core innovations of SharAcc include a multi-shard architecture with attribute management shards and a validation shard, an improved Merkle Patricia Trie (iMPT) for efficient user attribute storage and management, a Merkle Directed Acyclic Graph (Merkle DAG) for precise transaction recording and verification, and a batch consensus mechanism based on skip lists to ensure efficient transaction verification. Experimental results demonstrate that SharAcc effectively overcomes the scalability and security limitations of existing ABAC schemes, achieving a throughput of up to 10,000 transactions per second and a confirmation latency reduced to as low as 200 ms. This decentralized design and sharded blockchain approach offer new perspectives for future access control systems.