Security properties are often focused on the technological side of the system. One implicitly assumes that the users will behave in the right way to preserve the property at hand. In real life, this cannot be taken for granted. In particular, security mechanisms that are difficult and costly to use are often ignored by the users, and do not really defend the system against possible attacks. Here, we propose a graded notion of security based on the complexity of the user's strategic behavior. More precisely, we suggest that the level to which a security property $\varphi$ is satisfied can be defined in terms of (a) the complexity of the strategy that the voter needs to execute to make $\varphi$ true, and (b) the resources that the user must employ on the way. The simpler and cheaper to obtain $\varphi$, the higher the degree of security. We demonstrate how the idea works in a case study based on an electronic voting scenario. To this end, we model the vVote implementation of the \Pret voting protocol for coercion-resistant and voter-verifiable elections. Then, we identify "natural" strategies for the voter to obtain receipt-freeness, and measure the voter's effort that they require. We also look at how hard it is for the coercer to compromise the election through a randomization attack.
翻译:安全性财产往往集中在系统的技术方面。 隐含地假设用户会以正确的方式维护手头的财产。 在现实生活中,这不能被认为是理所当然的。 特别是, 用户往往忽视了使用困难和昂贵的安全机制, 并且并不真正保护系统不受可能的攻击。 我们在这里根据用户战略行为的复杂性提出一个分级的安全性概念。 更准确地说, 我们建议, 可以用以下几个方面来界定安全性财产是否满意: (a) 选民需要执行的战略的复杂性, 以使美元成为真实的; (b) 用户在路上必须使用的资源。 获得美元更简便和便宜, 安全程度越高。 我们根据电子投票的情景在案例研究中展示了这个概念是如何起作用的。 为此, 我们用强制抗争和选民可核实的投票协议的模范。 然后, 我们为选民确定“ 自然” 战略, 如何在路上获得接收自由, 并测量选举的难度。