purchasers, and the infeasibility of meeting certain requirements. The software problem is a complex one, and it is not clear that a specific and evidently correct solution is possible. The end users—voters and local election officials—are not likely to be able to understand the code themselves or to appreciate the implications of its complexity for errors. Inappropriate collaboration between local politicians and the vendor, along with the ability to control the setup of the ballot, may be problematic not only because of potential malfeasance but also because neither the vendor nor the politicians are likely to be experts in designing usable ballots. Requirement specification may also be problematic if the requirements mandated in legislation are technically infeasible or unspecific.
It was observed that electronic voting systems pose a fundamentally harder challenge than many other safety-oriented critical systems because of the high risk of motivated, malicious attack. Because voting is so foundational to our democracy and because there are strong incentives for rogue states, terrorists, political parties, special-interest groups, and even individuals to influence election results, the threat of attack on such systems is highly likely. One panelist estimated that in the current system bribing only a handful of people could allow serious compromise. At the moment, large-scale attacks on medical and avionics system software are relatively minimal; there seems to be little motivation for such attacks because these types of systems tend to be very distributed and physically inaccessible. Accordingly, certification in these domains has evolved without much attention to the kinds of adversaries that voting systems might face,14 although there is increasing concern that such systems may themselves become targets of attack.
The difficulty in identifying the user of the system creates additional challenges for building dependable and certifiable voting systems. In most system development environments, there is a user who can evaluate the delivered system for fitness of purpose, and the same party that evaluates the system has the primary vested interest in its quality. For voting systems, there is no single user. Local election officials play a key role in acquiring and managing these systems, but it is arguably the voter who is the true user. Unfortunately, the voter has little influence on the process of acquisition and certification, and cannot easily even assess how likely it is that his or her vote was recorded correctly.