Biblio

In this paper, we propose an access control model featured with the efficient key update function in data outsourcing environment. Our access control is based on the combination of Ciphertext Policy - Attribute-based Encryption (CP-ABE) and Role-based Access Control (RBAC). The proposed scheme aims to improve the attribute and key update management of the original CP-ABE. In our scheme, a user's key is incorporated into the attribute certificate (AC) which will be used to decrypt the ciphertext encrypted with CP-ABE policy. If there is any change (update or revoke) of the attributes appearing in the key, the key in the AC will be updated upon the access request. This significantly reduces the overheads in updating and distributing keys of all users simultaneously compared to the existing CP-ABE based schemes. Finally, we conduct the experiment to evaluate the performance of our proposed scheme to show the efficiency of our proposed scheme.

In the security protocols of Efficient Mesh Security Association(EMSA), the key updating strategy is an effective method to ensure the security of communication. For the existing strategy of periodic automatic key updating, the PTK(Pairwise Transit Key) is updated through the complex 4-way handshake to produce each time. Once the update frequency of the PTK is faster, it will have a greater impact on throughput and delay of the network. On this basis, we propose a new strategy of dynamic key updating to ensure the safety and performance of wireless mesh networks. In the new strategy, mesh point(MP) and mesh authenticator(MA) negotiate a random function at the initial certification, and use the PTK which is generated by the 4-way handshake as the initial seed. When the PTK updating cycle comes, both sides generate the new keys using the random function, which do not have to generate a new PTK by complex 4-way handshake. The analysis of performance compared with existing strategies showed that the dynamic key updating strategy proposed in this paper have a larger increase in delay and throughput of the network.