ning, checking password, and other security issues. Service Delivery Platforms 3. Communication interfaces-used for making and exchanging messages with the SWEB server platform (SOAP messages, time-stamp requests, etc.). 4. Store interfaces-used to load resources to and from stores. Store can be file system, RMS, KeyStore, or something else. According to the specific design of GUI which relays on XML file definitions, there is no direct call between GUI implementations and other interface groups. Indirectly, all three other interface implementations can be called in GUI via devel- oped service mechanism defined in XML files. It means that GUI can be developed separately from three other implementations. The core functionality of mobile application includes APIs for sending and receiving protected XML messages. The security functionality is implemented in the following modules: XML encryption module-provides an interface to the XML Encryption procedure. XML digital signature module-provides an interface to the XML Digital Signature procedure. WS-Trust (STS) module-the interface is used to establish the communica- tion with the STS Server in order to get the SAML token. WS-security module-provides an interface to WS-Signature and WS-Encryption procedures. Time-stamping module-enables the communication with a TTP (Time- Stamping Authority, TSA) in order to obtain certified time data that will be cryptographically bound to a document. XKMS module-the interface is used to establish the communication with the XKMS Server in order to locate and validate certificates. Certificate module-the interface which is used to access and parse the X.509v3 electronic certificate stored in JAVA store of the mobile phone. WebService module-provides an interface to the SOAP parser module. The SOAP parser is built on a generic XML parser with special type-mapping and text data-marshalling mechanisms. Software and tools used for the development of Java mobile application are NetBeans IDE 5.5 development tool-vendor Sun Microsystems Inc.