Mobile Grid, is a full inheritor of the Grid with the additional feature that it supports mobile users and resources. Security is an important aspect in Grid based systems, and it is more complex to ensure this in a mobile platform owing to the limitations of resources in these devices. A Grid infrastructure that supports the participation of mobile nodes and incorporates security aspects will thus play a significant role in the development of Grid computing. The idea of developing software through systematic development processes to improve software quality is not new. However, many information systems such as those of Grid Computing are still not developed through methodologies which have been adapted to their most differentiating features. The lack of adequate development methods for this kind of systems in which security is taken into account has encouraged us to build a methodology to develop them, offering a detailed guide for their analysis, design and implementation. It is important to use software V&V techniques, according to IEEE Std. 1012 for Software Verification and Validation, to ensure that a software system meets the operational needs of the user. This ensures that the requirements for the system are correct, complete, and consistent, and that the life-cycle products correctly design and implement system requirements. This paper shows part of a development process that we are elaborating for the construction of information systems based on Grid Computing, which are highly dependent on mobile devices in which security plays a highly important role. In the design activity of the process, we design a security architecture which serves as a reference for any mobile Grid application that we wish to build since this security architecture defines a complete set of security services which will be instantiated depending on the requirements and features found in previous activities of the process. A V&V task is also defined in the design activity to validate and verify both the architecture built and the traceability of the artifacts generated in this activity. In this paper, we will present the service-oriented security architecture for Mobile Grid Systems which considers all possible security services that may be required for any mobile Grid application.