Building a reliable e-voting system: functional requirements and legal constraints

We are in the process of producing a common user requirement specification for electronic voting systems, based on a generic voting model that takes into account: a) the existing European legal framework, b) organizational details of conventional voting processes, c) the required security attributes, and d) opportunities offered and constraints imposed by state-of-the-art technology. The requirements elicitation process has been based on the rational unified process with each "use case" referring to a functional requirement of the system. Its "security attributes" (mainly imposed by the legal framework) are being expressed as non-functional requirements which are either "use case specific" or "system wide".