As the killer application of the wireless internet, the LBS (Location-based Services) has reconsidered technology about location determination technology, LBS middleware server for various application, and diverse contents processing technology. For this kind of LBS, the role of security service is very important in the LBS that store and manage the location information of mobile devices and support various application services using those location information. And in all phases of these functions that include acquisition of location information, storage and management of location information, user management including authentication and information security, and management of the large-capacity location information database, safe security service must be provided. This paper describes a key management architecture based on XML standards for securing access to location based information and services. The main characteristic of the approach is that it build on a number of XML-based standards.