Private data is easy to suffer from the attacks about data confidentiality, integrity and freshness. To resolve this problem, a secure data aggregation algorithm based on homomorphic Hash function was proposed, called HPDA (High-Efficiency Privacy Preserving Data Aggregation) algorithm. Firstly, it used homomorphic encryption scheme to provide data privacy-preserving. Secondly, it adopted homomorphic Hash function to verify the integrity and freshness of aggregated data. Finally, it reduced the communication overhead of the system by improved ID transmission mechanism. The theoretical analyses and experimental simulation results show that HPDA can effectively preserve data confidentiality, check data integrity, satisfy data freshness, and bring low communication overhead.
An algorithm based on random Dijkstra algorithm and applying genetic algorithm to solve SPDRGS(Shortest Path problem on Dynamic Route Guidance System) was proposed. By applying random Dijkstra algorithm, the algorithm cleared out the biggest obstruction between the genetic algorithm and SPDRGS, which is how to get the initial generation of GA(Genetic algorithm). According to DRGS’s (Dynamic Route Guidance System) demand for time complexity and network constraint condition of route guidance algorithms, this algorithm can quickly find the excellent path and does not need any network constraint condition, which also can solve the problems on continuously and discrete dynamic networks. So the algorithm proposed can satisfy the demand of DRGS.