Research On Privacy Preservation In WiFi Fingerprint Based Indoor Localization

With the continuous development of society and the popularity of smart mobile terminal,the location based service(LBS)has become increasingly important in our daily life.When we enjoy the convenience of LBS,our location information is prone to leakage.Leakage of location information will expose our personal privacy,and cause social honor or economic losses.Location service is an important branch and foundation of LBS services.It is of great significance to study the privacy protection in the process of location service.WiFi Fingerprint-based localization is regarded as one of the most promising techniques for indoor localization.In this paper,we mainly study the privacy protection based on WiFi fingerprint indoor localization,and propose two WiFi fingerprint indoor localization schemes based on user location privacy protection.In this paper,we summarize the principle of indoor positioning technologies,and introduce the process and principle of indoor positioning based on WiFi fingerprint in detail.Based on the structure of the indoor location system based on WiFi fingerprint,this paper analyzes the factors that cause the leakage of user's location information and the key protection direction.k-anonymous technology is one of the most common location privacy preservation technologies.In this paper,k anonymous technology is applied to the user location privacy preservation based on WiFi fingerprint indoor location.Frequently,entropy is used to measure the performance of k anonymous algorithm.Based on the maximum entropy condition,this paper proposes a k anonymous algorithm based on WiFi fingerprint location,and gives the detailed steps and system structure of privacy protection scheme in indoor localization.It is proved theoretically that the privacy preserving performance of the proposed k anonymous algorithm.We also study the application of homomorphic encryption to protect user's location privacy in WiFi fingerprint based indoor localization.This paper analyzes the principle of Paillier encryption algorithm and the improvement scheme.Based on the principle of Paillier encryption,a homomorphic encryption scheme is designed to protect users' location based on WiFi fingerprint indoor localization.We put forward the complete procedure of homomorphic encryption indoor location scheme.It is proved theoretically that the proposed scheme will not affect the localization results and is able to protect the user's location privacy effectively.We achieve the basic function of indoor positioning based on WiFi fingerprint in laboratory equipment and environment.On the basis of the above,this paper makes simulation experiments of k anonymous and homomorphic encryption privacy preservation scheme.The experimental results show that the output entropy of the proposed k-anonymity algorithm is close to the ideal value,calculation overhead of homomorphic encryption scheme in each stage is very large.Finally,we make a comparative analysis of k anonymous and homomorphic encryption privacy preservation schemes,and summarize the advantages and disadvantages of the two schemes.