An authenticated asymmetric group key agreement based on attribute encryption

Secure communication among terminals in a group is necessary in Internet of Things (IoT). Such as, the Vehicular Ad-hoc Network (VANET) is used to communicate with the vehicles to give alert for weather conditions, road defects, traffic conditions, etc. However, people are also worried about two major security issues: privacy and authentication. Under an open and untrusted network, common secret keys which are negotiated by group terminals through group key agreement are used to realize encryption communication among group members. Personal identity information is exposed and privacy cannot be protected under the traditional identity-based authenticated asymmetric group key agreement protocol. Therefore, an authenticated asymmetric group key agreement based on attribute encryption (ABE-AAGKA) is proposed, which combines the advantages of attribute encryption and identity authentication. Attribute encryption and authentication techniques are adopted to guarantee the secure of group key agreement, and protect the personal privacy. Moreover, calculate and communicate loads are able to be moved to powerful server through the protocol to reduce the workload on intelligent terminal under the imbalanced mobile networks. The proposed protocol is proven to be secure under the inverse computational Diffie-Hellman (ICDH) problem assumption. Performance analysis shows that the proposed scheme is more efficient than existing works.