Location-based service (LBS) is the concept that denotes applications integrating geographic location (i.e., spatial coordinates) with the general notion of services. Examples of such applications include emergency services, car navigation systems, tourist tour planning etc. The increasing spread of location-based services (LBSs) has led to a renewed research interest in the security of services. To ensure the credibility and availability of LBSs, the needed requirement is to address access control, authentication and privacy issues of LBSs. In this paper a study of the encryption techniques used for ensuring the security of location-based services (LBSs) is done. According to our discussion, the approach can meet the confidentiality, authentication, simplicity, and practicability of security issues. As a result, the proposed encryption techniques can also meet the demands of mobile information systems.