Location privacy is one of the major security problems in a Wireless Personal Area Network (WPAN). By eavesdropping on the transmitted packets, an attacker can keep track of the place and time of the communication between the mobile devices. The hardware address of the device can often be linked to the identity of the user operating the mobile device; this represents a violation of the user’s privacy. Fortunately, this problem can be solved quite efficiently in a WPAN. We consider four communication scenarios and present several techniques to solve the location privacy problem in each of these scenarios. As mobile devices in a WPAN are typically operated by a user and energy constrained, we focused on user-friendliness and energy consumption during the design of our solutions. Categories and Subject Descriptors C.2.0 [Computer-Communication Networks]: General— Security and protection General Terms Algorithms, Security Keywords Location privacy, Bluetooth, pseudonyms