Analysis of 3GPP SAE Access Stratum Security Protocol

The Safety streams of LTE/SAE system include AS (Access Stratum) and NAS (Non-Access Stratum) two security levels. The AS security is the security between the UE (User Equipment) and eNB (evolved Node-B), mainly to complete the encryption and integrity protection for AS signaling, the integrity protection for the data of UP (User Plane). In this paper, through the analysis of the SAE security architecture protocol, We describe the security access layer activation process and algorithm selection process, analyze the implementation algorithm of SAE access layer encryption and integrity mechanism. At the same time, it also introduces the common algorithm used in encryption and integrity protection algorithm-SNOW 3G algorithm, and the cost in terms of time and space of encryption and integrity protection algorithm are analysed.