Performance and Comparison Clause Samples

Performance and Comparison. In this section, the proposed scheme is compared with existing schemes [8,16,22] in terms of computation overhead. Jiang, Zhu and Wang [22] proposed a conditional privacy (ACP) scheme based on anonymized batch authentication in vehicular ad hoc networks. Hai [8] proposed an authenticated group key Agreement (AGKA) scheme for mobile communication based on bilinear. For comparison, only the time-consuming multiplication/division and bilinear pairing operations are considered, and the other efficient operations such as point addition are omitted. Let Tpar be the execution time of a pairing operation, Tmul be the execution time of performing a scale multiplication over an elliptic curve, Terminal be the user terminal node, and ACS be the access control server. The comparison is summarized in Table 2. As shown in Table 2, every procedure of our scheme enjoys constant computing costs, whereas the costs of existing schemes are linear with the group size. With the increase of the number of vehicles, the advantages of our scheme are more and more obvious, that is, the computation costs would not increase. Since both our scheme and ACP use the batch verification method, RSU takes less computations than the other two schemes. Note that OBU in [22] should take n multiplications, which requires more computation resources than our scheme. Although the computation cost of OBU in [8] is the same as that of our scheme, there requires a complicated certificate management mechanism, which affects the overall secret key negotiation efficiency. Table 2. Computation Overhead Comparison. ACP [22] nTmul 3Tpar + (2n + 1)Tmul AGKA [8] 3Tpar + Tmul (2n 1)Tpar + (n + 1)Tmul SADEGKA [16] 2nTpar + 5nTmul 2nTpar + 4nTmul Our scheme 3Tpar + Tmul 3Tpar + Tmul We conducted experiments on a system with Intel(R) Core(TM) i5-5200U CPU at 2.20 GHz and