Novel Security And Privacy Preserving Approaches For Next-generation Mobile Internet

The rapid development and wide application of the mobile Internet,has greatly changed the life of modern human beings.For example,based on the mobile Internet platform,sharing economy(such as sharing cars,bikes,and online short-term renting)makes our life more convenient,further reducing transaction costs and improving resource utilization.The popularity of wearable devices,smart home and intelligent industry,enhances the interconnection of everything through mobile Internet.The diversity of consumption scenarios,the integration of online and offline services,promote the refinement of mobile applications,and a group of new service paradigms have emerged to provide users with brand new life experience.However,there are many problems behind the prosperity of mobile Internet,among which preserving mobile users' privacy is a critical one.First of all,the mobile smart device is a very private equipment,storing large amount of users' privacy information.But it is hard to achieve the absolute security of mobile device due to users' habits and limitations of current security techniques.Meanwhile,the smart mobile phone or other network entrance equipped with diverse sensors can produce various data related to the user.This kind of private data is collected,stored,analysed and shared.Consequently,the smart mobile phone knows everything about its owner,or even know more than its owner.In addition,some mobile Internet service providers will collect,mine or even buy mobile users' private information for some business purposes.Our habits,every action and every move are recorded for further analysis.Therefore,everyone becomes more transparent in the mobile Internet era.The security and privacy protection of mobile user's personal information becomes the key to the development of mobile Internet.Unfortunately,none of the existing work has perfectly solved the privacy problems in mobile Internet.This motivates our effort to do more feasible and valuable researches on this issue.In this dissertation,we design efficient privacy-preserving mechanisms from three perspectives,including the terminal users,service providers,and terminal devices.We consider a variety of application services,containing participatory sensing,social networks,device pairing,and etc,and propose corresponding security and privacy solutions based on various techniques adopted from cryptography,non-cryptography,game theory,physical security,to solve different kinds of privacy and security problems in the mobile Internet.My research work presented in this dissertation focuses on three critical categories,including privacy-preserving mechanism design in participatory sensing networks,privacy-preserving social networks,and secure pairing in D2 D communication,and the specific contributions are listed as follows.1.For participatory sensing networks,we propose SLICER,which is the first kanonymous privacy preserving scheme for participatory sensing with multimedia data.SLICER integrates a data coding technique and message transfer strategies,to achieve strong protection of participants' privacy,while maintaining high data quality.We study two kinds of data transfer strategies,TMU and MCT,to achieve better system performance.Furthermore,we have implemented SLICER and evaluated its performance using publicly released taxi traces.The evaluation results show that SLICER achieves high data quality,with low computation and communication overhead.2.For privacy-preserving social networks,we consider the label-neighborhood attack model,which means attackers obtain both network structure and labels of one-hop neighbors as background knowledge.We propose a global similaritybased group anonymization method to anonymize social network structure while maintaining data values as much as possible.We also consider privacy problem in dynamic social networks,and present an incremental approach to achieve efficient privacy protection.Finally,We evaluate our approach on several data sets and results show that we can well protect users' privacy while maintaining data values in social networks.3.For key extraction problems in terminal devices,we propose MAGIK,a secure and efficient key establishment scheme based on dynamic geomagnetic field in indoor environment.We carefully study the feasibility of utilizing indoor geomagnetic field for key extraction through extensive measurements.We also optimize the key extraction process and present two rotation-angle-based quantification methods,which can achieve faster key generation rates and lower bit mismatching ratios.Besides,we build a prototype on commodity mobile devices,and evaluate its performance by conducting real-word experiments.The results confirm that our system is efficient,in terms of key extraction rate,and robust in secret key establishment without requiring additional overhead on mobile devices.4.For devices' secure pairing problems,we propose SAFE,a secure and fast device pairing mechanism based on dynamic electromagnetic field in indoor environments.We demonstrate that the indoor electromagnetic filed is a proper medium to do device pairing between wireless devices in physical proximity through extensive measurements and observations.We also propose a new Time-Series quantization method and an extended optimization technique called Pre-Match to make it faster and safer,even in the environments with weak signals.We implement an Arduino-based prototype at a very low cost,and evaluate its performance.The results confirm that SAFE achieves secure device pairing with a high key bit rate,while maintaining a high confidentiality without additional overhead on mobile wireless devices.