Fine-grained data cross-domain access control policy based on ciphertext policy attribute encryption

As the big data technique rapidly develops, the demand for inter-agency cross-domain data sharing is growing, but there is a risk of unauthorised access in cross-domain data sharing. To this end, this paper first improves the ciphertext policy attribute-based encryption (MCACP-ABE), which achieves fine-grained protection of cross-domain data by authorising cross-domain third parties and attribute authority centres, and introduces the accountability tracking module. On this basis, fine-grained data cross-domain access control (AC) policies are designed. The policy designs a cross-domain AC structure based on MCACP-ABE, which realises fine-grained data access protection through a cross-domain negotiation component, a rule mapping component, and a cross-domain encryption component. The security analysis and simulation outcome imply that the offered policy not only satisfies indistinguishable security under chosen ciphertext attack (IND-CCA) but also has high cross-domain communication efficiency, which improves the security and usability of data cross-domain access.