In this paper, we establish our child safety system model related to the addressing contradictory issue of wireless sensor networks caused by the mutual authentication and privacy protection of an end-user. Based on the system model, we propose the novel location-aware and privacy-preserving approach for providing child safety over wireless sensor networks. Although we illustrate our protocol over the sensor networks, the proposed protocol can be operated by various wireless networks (e.g., WiFi and UWB) which can support RSSI (Received Signal Strength Indication). Compared to a few previous works, the proposed approach can show the potential of enhancing accuracy with location information, preserve the privacy of an end-user, and provide the capability of controlling the child safety service to an end-user.

Recently, numerous service discovery protocols have been introduced in the open literature. Unfortunately, many of them did not consider security issues, and for those that did, many security and privacy problems still remain. One important issue is to protect the privacy of a service provider while enabling an end-user to search an alternative service using multiple keywords. To deal with this issue, the existing protocols assumed that a directory server should be trusted or owned by each service provider. However, an adversary may compromise the directory server due to its openness property. In this paper, we suggest an efficient verification of service subscribers to resolve this issue and analyze its performance and security. Using this method, we propose an efficient and secure service discovery protocol protecting the privacy of a service provider while providing multiple keywords search to an end-user. Also, we provide performance and security analysis of our protocol.