Improved 5G-AKA Scheme Based on Identity Pool and Bloom Filter

5G-AKA is an identity authentication protocol for 5G network that ensures communication security, such as the network and subscribers. However, the existing standards simply associate 5G Globally Unique Temporary UE Identity (GUTI) with the Subscription Permanent Identifier (SUPI) in the Home Network (HN) as a temporary identity solution for 5G subscribers, UE cannot quickly change the 5G-GUTI according to its own needs. Moreover, the current Sequence Number (SQN) synchronization mechanism will cause low authentication efficiency in the specific situation. To address the above issues, we use Bloom filter to establish a many-to-one mapping relationship between the identity and the UE, so as to achieve rapid verification of the identifier. Based on this, a mechanism that allows the UE to change the temporary identity and a fast authentication mechanism under the condition of sequence out-of-synchronization are proposed. Security analysis and experimental results demonstrate that the proposed scheme is efficient, secure, and compatible with the existing system.