TBAC: Transaction-Based Access Control on Blockchain for Resource Sharing with Cryptographically Decentralized Authorization

In this paper we focus on a new generation of secure resource sharing platform in a decentralized blockchain environment with flexible and diverse permission management, as well as verifiable and transparent access process. To do it, we present a new Transaction-based Access Control (TBAC) platform which integrates the standard attribute-based access control (ABAC) model and the blockchain system. In this platform, four types of transactions and Bitcoin-type cryptographic scripts are presented to describe the TBAC access control procedure corresponding to subject registration, object escrowing and publication, access request and grant. We also present a cryptosystem associated with TBAC (CryptoTBAC) for ensuring secure attribute-exchanging and decision-making of dynamic policy. We evaluate the security of CryptoTBAC from three aspects: transaction, authorization, and decision-making security.