Abstract Complexity of voting manipulation is a prominent topic in computational social choice. In this work, we consider a two-stage voting manipulation scenario. First, a malicious party (an attacker) attempts to manipulate the election outcome in favor of a preferred candidate by changing the vote counts in some of the voting districts. Afterwards, another party (a defender), which cares about the voters' wishes, demands a recount in a subset of the manipulated districts, restoring their vote counts to their original values. We investigate the resulting Stackelberg game for the case where votes are aggregated using two variants of the Plurality rule, and obtain an almost complete picture of the complexity landscape, both from the attacker's and from the defender's perspective.

中文翻译：

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通过重新计票保护选举

摘要 投票操作的复杂性是计算社会选择中的一个突出话题。在这项工作中，我们考虑了一个两阶段的投票操纵场景。首先，恶意方（攻击者）试图通过更改某些选区的投票数来操纵选举结果，以支持首选候选人。之后，另一方（捍卫者）关心选民的意愿，要求在被操纵地区的一个子集中重新计票，将他们的投票数恢复到原始值。我们针对使用 Plurality 规则的两个变体聚合投票的情况调查了由此产生的 Stackelberg 游戏，并从攻击者和防御者的角度获得了复杂性格局的几乎完整图景。