| 抄録（英） |
Although LBS(Location Based Service) is quite convenient and usually used these days, The location privacy of the user is not guaranteed from the LBS. If LBS itself is malicious, It is dangerous what the user’s raw location data sends to the LBS. The promising approach to protect the user’s location privacy is utilizing the dummy which is the fake location of the user. In the conventional schemes, the users themselves or the TTPS (Trusted Third Party Server) generates the dummies and sends them to the LBS with his/her real location. However, these schemes have shortcomings. In case of the user generates the dummies, the computational cost is high on the user’s mobile devices. In these cases, the communication cost is also high since the user must receive all data of the dummies locations.\r\nIn this paper, in order to overcome shortcomings what mentioned above, we propose the Cost Effective Dummy Generation Scheme Based on Non-Trusted LBS. The main idea of our scheme is that Non-Trusted LBS creates dummy locations which include user’s real location for reducing the user’s communication cost. In spite of allowing LBS to generate the dummy location, the user’s location privacy is protected. Through the XOR operation, the user’s value is restored and protected from the LBS which is malicious. The LBS receives all of random number and the user’s converted coordinate and performs the XOR operation, the LBS can generate multiple dummy locations which include his/her real location. Furthermore, in order to reduce communication cost, we combine our scheme with PIR-based method. Our method is enable the user to receive only him/her data by hiding the information which is him/her searched places from the LBS. We demonstrate the reduction of the communication cost and the the reliability of our scheme by the computer simulation and the analysis. |