SaTC: CORE: Small: Practical and Robust Hidden Voice Commands

亚马逊的Alexa、谷歌Home和苹果的Siri等系统允许用户向个人数字助理发出语音命令和提出问题。 由于这些系统通常可以访问敏感数据并且可以执行具有严重影响的任务（例如，花钱购物），对他们的攻击可能会产生重大后果。 不幸的是，最近的研究表明，对这种基于语音的接口的攻击是可行的。该项目正在探索保护智能手机和其他设备的语音接口的方法，以确保仅接受设备所有者的命令。研究人员最近引入了隐藏语音命令的概念：被计算机语音识别系统解释为语音命令的音频，但人类听众无法理解。 从理论上讲，攻击者可能会使用隐藏的语音命令来秘密控制受害者的智能手机和其他电子设备。 这在实践中是一个现实的威胁吗？该项目正在研究这一威胁的实际性和保护办法。 首先，研究人员正在调查攻击者是否可以有效地、隐蔽地构建隐藏的语音命令，并使这些命令在现实条件下运行，以规避先前提出的防御措施。 其次，他们正在开发可扩展的检测技术和防御措施，以可靠有效地防止此类攻击。

Systems like Amazon's Alexa, Google Home and Apple's Siri allow users to issue voice commands and pose questions to personal digital assistants. Since these systems often have access to sensitive data and can perform tasks with serious impact (e.g., spend money to make a purchase), attacks against them could have significant consequences. Unfortunately, recent research has shown that attacks against such voice-based interfaces are feasible. This project is exploring methods of securing the voice interfaces to smartphones and other devices to ensure that commands are only accepted from the devices' owners. The researchers recently introduced the notion of hidden voice commands: audio that is constructed to be interpreted as voice commands by a computer speech recognition system, but is incomprehensible to human listeners. In theory, attackers may use hidden voice commands to surreptitiously control victims' smartphones and other electronic devices. Is this a realistic threat in practice? This project is studying both the practicality of this threat and approaches to protection. First, the researchers are investigating whether an attacker could construct hidden voice commands efficiently and covertly and make the commands operate under realistic conditions to circumvent previously proposed defenses. Second, they are developing scalable detection techniques and defenses that reliably and efficiently prevent such attacks.