Personal voice assistants (PVAs) are increasingly used as interfaces to digital environments. Voice commands are used to interact with phones, smart homes, or cars. In the United States alone, the number of smart speakers, such as Amazon’s Echo and Google Home, has grown by 78% to 118.5 million, and 21% of the U.S. population own at least one device. Given the increasing dependency of society on PVAs, security and privacy of these have become a major concern of users, manufacturers, and policy makers. Consequently, a steep increase in research efforts addressing security and privacy of PVAs can be observed in recent years. While some security and privacy research applicable to the PVA domain predates their recent increase in popularity, many new research strands have emerged. This article provides a survey of the state of the art in PVA security and privacy. The focus of this work is on the security and privacy challenges arising from the use of the acoustic channel. Work that describes both attacks and countermeasures is discussed. We highlight established areas such as voice authentication (VA) and new areas such as acoustic Denial of Service (DoS) that deserve more attention. This survey describes research areas where the threat is relatively well understood but where countermeasures are lacking, for example, in the area of hidden voice commands. We also discuss work that looks at privacy implications; for example, work on management of recording consent. This survey is intended to provide a comprehensive research map for PVA security and privacy.

中文翻译：

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个人语音助理安全和隐私调查


个人语音助理 (PVA) 越来越多地用作数字环境的接口。语音命令用于与手机、智能家居或汽车交互。仅在美国，亚马逊 Echo 和 Google Home 等智能音箱的数量就增长了 78%，达到 1.185 亿台，21% 的美国人口至少拥有一台设备。鉴于社会对 PVA 的依赖日益增加，其安全和隐私已成为用户、制造商和政策制定者的主要关注点。因此，近年来针对 PVA 安全和隐私的研究工作急剧增加。虽然一些适用于 PVA 领域的安全和隐私研究早于它们最近的流行，但许多新的研究领域已经出现。本文对 PVA 安全和隐私的最新技术进行了调查。这项工作的重点是解决使用声学通道带来的安全和隐私挑战。讨论了描述攻击和对策的工作。我们重点介绍语音身份验证 (VA) 等成熟领域和声学拒绝服务 (DoS) 等值得更多关注的新领域。这项调查描述了对威胁相对了解但缺乏对策的研究领域，例如隐藏语音命令领域。我们还讨论了关注隐私影响的工作；例如，记录同意的管理工作。本次调查旨在为 PVA 安全和隐私提供全面的研究图谱。