In the cloud environment, the data access policy based on the traditional attribute-based encryption(ABE) technology in the session key agreement protocol cannot reflect the complex relationships of many attributes, which leads to the lack of user authentication ability and the flexibility. To solve the problem, this paper presented a user authentication structure of linear secret sharing scheme(LSSS) based on the attached condition expression of complex attribute relations, and introduced an attribute-based key agreement protocol based on the structure. The protocol realized a more general user authentication policy based on user attributes, maintained the fuzzy identity authentication feature, and provided the exchange of session keys between the users who both met the conditions of the attribute relationships. Under the attribute-based Blake-Johnson-Menezes(AB-BJM) model, the security model of selective access structure and the decisional q-parallel bilinear Diffie-Hellman exponent(q-PBDHE) hypothesis, the protocol proves to be secure. Compared and analyzed the similar protocols through experiment, the protocol has better performance in the application scenarios containing the more complicated relationships of attributes, and has wide application prospect.

[2021-11-29] Accepted Paper /doc/2021.06.0365/v1

[2022-04-05] Printed Article /doc/2021.06.0365/v2