E-voting: Dependability requirements and design for dependability

Elections are increasingly dependent on computers and telecommunication systems. Such "E-voting" schemes create socio-technical systems (combinations of technology and human organisations) that are complex and critical, as the future of nations depends on their proper operation. Thus heated debate surrounds their adoption and the possible methods for making them demonstrably dependable. We discuss the dependability requirements for such systems, and the design issues in ensuring their satisfaction, with reference to a recent proposal that uses cryptography for fault tolerance, in order to avoid some of the perceived dangers of electronic voting. Our treatment highlights the need for considering the whole socio-technical system, and for integrating security and fault tolerance viewpoints.