A Scheme for using Location Based Services anonymously in Mobile Cloud Computing Fizza Abbas, Rasheed Hussain, Junggab Son, Hasoo Eun and Heekuck Oh Dept. of Computer Science and Engineering, Hanyang University, South Korea fizza_alvi85@yahoo.com, hkok@hanyang.ac.kr Abstract: Mobile cloud computing is getting popular in recent years because of the advancement in the field of telecommunication. It not only provides a cheap solution for processing and storage of a user’s data remotely but also provides services like Location based services. These services can be described as a class of computer program level services which facilitate users by providing them with various types of information based on their location. These informative services provided by Location based services are used in various contexts which include health, entertainment, parcel and vehicle tracking as well as social life to name a few. On the other hand protecting user’s location’s privacy is a significant challenge to the Mobile world. The Location based service provider faces privacy issues when mobile user provides his/her current location and anyone can trace his/her activities. In this paper we present a homomorphic encryption based scheme to preserve location privacy of user while still getting location based services anonymously. Our partial encryption scheme for location data not only attempts to reduce encrypted data sent to location based service provider but also minimizes its processing. Keywords: Homomorphic encryption, Location based service and Mobile cloud computing. I. INTRODUCTION With the growth of Mobile devices, people not only communicate with each other without being bounded by time and place but are also being facilitated with many services used by mobile applications (such as Google apps, iPhone apps). Mobile computing is growing rapidly but on the other hand facing problems regarding security, mobility, storage, bandwidth and battery life time. To overcome these problems the developers move to combine cloud computing with mobile computing. Cloud computing is one of the powerful trends in IT technology .It provides lower computing costs, improved performance, reduced software costs, instant software updates, improved document format compatibility, unlimited storage capacity, device independence, and increased data reliability. With the added flavor of Mobile cloud computing (MCC), it serves as edged sword which gives new services and facilities users to take advantage of both mobile computing and cloud computing. In global market mobile applications increase their share and many applications are being introduced based to run on MCC like mobile commerce, mobile learning, mobile health care, mobile gaming, sharing photo and videos. MCC refers to an infrastructure where both the data storage and the data processing happen outside of the mobile device. Mobile cloud applications move the computing power and data storage away from mobile phones and into the cloud, bringing applications and mobile computing to not just smartphone users but a much broader range of mobile subscribers. Beside all these advantages of MCC, it suffer from some issues including low bandwidth due to wireless network as compared to wired network, heterogeneity, problems to handle computing offloading, security , privacy, integrity, authentication and digital right management, In this paper we focus on privacy issues. We highlight the concerns related to location privacy of a user when mobile user is enjoying the facility of location based services in MCC environment, and also propose a scheme that preserve location privacy of a user while using location based service anonymously in MCC [1]. Fig1. MCC Architecture [9] The architecture of MCC is shown in Fig 1. It includes mobile client, Mobile network provider and Cloud service provider. The mobile devices are connected to the Mobile network through BTS that establish connection between the cloud provider and mobile user. Mobile users request for services to mobile network and in turn mobile network operator gives response according to the user’s data stored in databases. After that the user’s request forwarded to cloud through internet [9]. The rest of the paper is organized as follow. Section II provides motivation towards proposed scheme. Section III gives literature background of the