f using XML Key Management Specification (XKMS) protocol [4] in the proposed e/m-government system. The XKMS protocol constitutes a lightweight front end for accessing PKI services, possibly used in the wireless communication which should be of primary benefits. It enables the integra- tion of keys and certificates into mobile applications as well as the implementation of PKI X.509v3 digital certificate registration, revocation, and update mechanisms. Besides STS and XKMS, the client applications and the platform used also the time-stamping functionalities in order to create timely valid electronic documents with digital signatures of long-term validities. In this sense, a suitable TSA also represents an important part of the proposed model. Keeping in mind the above-mentioned text, the main contributions of the study are Proposal of a possible secure e/m-government model based on JAVA mobile/ desktop application and an SOA-based e/m-government platform Usage of secure JAVA mobile application in which all modern security tech- niques are implemented (XML-security, WS-security, SAML, time stamp- ing, PKI, and XKMS) which are used in an optimum way in order to cope with majority of security issues of the mobile Web Service communication Service Delivery Platforms Usage of SOA-based request-response e/m-government platform (Web Services) instead of session-based Web application platform which is far more suitable in the mobile communication systems Usage of XKMS service which is more suitable for mobile PKI system since it outsources complex operations such as PKI validation services to the external entity-the XKMS server, compared to usages of other techniques [4] The chapter is organized as follows: A description of the possible m-Govern- mental architecture is given in Section 11.2 while the possible m-Governmental scenario is considered in the Section 11.3. Section 11.4 is dedicated to the consider- ation about secure JAVA mobile Web Service application while conclusions are given in Section 11.5. 11.2 Possible 