关键词: WiFi指纹室内定位, 位置服务, 隐私保护, 差分隐私, 地理不可区分性

Abstract: In indoor localization services, WiFi fingerprinting technology has received widespread attention due to its extensive coverage  and high localization accuracy. However, for the online phase of location query, the user’s personal sensitive information is vulnerable to malicious attacks resulting in location privacy leakage. Existing WiFi fingerprintbased indoor positioning technologies primarily focus on single flat surfaces within indoor environments, which restricts the flexibility of WiFi deployment. When WiFi is deployed in multidimensional scenarios, addressing spatial location privacy issues becomes imperative. In this paper, a WiFi fingerprinting indoor localization privacy protection scheme based on geographic indistinguishability is proposed, in which the user generates a new received signal strength vector by using his own received signal strength and sends the obtained data to the location service provider through noise obfuscation, and introduces a digital signature technique to ensure that the client’s identity is not forged before obfuscating the position to be sent to the location service provider to achieve localization. Experimental results based on the simulation experimental platform show that the new scheme supports flexible deployment of WiFi, and is able to realize highprecision localization for the first time in the case of flexible deployment of 12 WiFi access points with guaranteed localization error of less than 1m while protecting location privacy.

Key words: WiFi fingerprint indoor localization, locationbased service, privacy protection, differential privacy, geographic indistinguishability