m-Government Architecture The proposed m-government model is presented in Figure 11.1 [1,3]. This model consists of Mobile users (citizen, companies) who send some Web Services requests to e/m-government platform based on Web Services for the purpose of receiving some governmental documents (e.g., residence certificate, birth, or marriage certificates, etc.). These users use secure JAVA mobile Web Service application for such a purpose. e/m government model STS server e/m government platform Citizen/company Figure 11.1 Proposed m-government model. On Secure JAVA Mobile Application Fixed/Desktop users connecting to the proposed Web Service governmental platform through some desktop secure Web Service application (could be JAVA based too). Since everything regarding functionality is similar and almost the same between the two client options, in the remaining part of the text we will consider only the secure JAVA Web Service mobile application and m-government solution model. Web Service endpoint implementation on the platform's side that imple- ments a complete set of security features-the same set as implemented in the secure JAVA mobile and the secure desktop applications. Well-processed requests with all security features positively verified, the Web Service plat- form's application proceeds to other application parts of the proposed SOA- based platform, including the governmental Legacy system for issuing actual governmental certificates requested. In fact, the proposed platform could completely change the application platform of some governmental organiza- tion or could serve as the Web Service "add-on" to the existing Legacy system implementation. In the latter case, the Legacy system will not be touched and only a corresponding Web Service interface should be developed in order to connect the proposed SOA-based platform and the Legacy govern- mental system. External entities, such as a PKI server with an XKMS server as a front end, UDDI, and TSA. 11.2.1 External Entities The following are the functions of th