A Survey Paper on Muti-Hop Privacy-Aware Data Aggregation in Mobile Sensing

With more increasing capabilities of mobile devices or we can say smart phones give rise to a variety of mobile sensing applications. This paper specifies how an untrusted aggregator in mobile sensing can periodically gain desired statistics over the data contributed by multiple mobile users, with privacy of each user. Although there are some existing works in this area, they either require both directional communications between the aggregator and mobile users in every aggregation period, or have high-computation overhead and cannot support large plaintext spaces. Also, they do not consider the Min aggregate, which is quite useful in mobile sensing. To address these problems, we propose an efficient protocol to obtain the Sum aggregate, which employs an additive homomorphic encryption and a novel key management technique to support large plaintext space. We also extend the sum aggregation protocol to obtain the Min aggregate of time-series data. To deal with dynamic joins and leaves of mobile users, a scheme proposed that utilizes the redundancy in security to reduce the communication cost for each join and leave