Abstract
Face recognition (FR) technologies are increasingly used to power large-scale image retrieval systems, raising serious privacy concerns. Services like Clearview AI and PimEyes allow anyone to upload a facial photo and retrieve a large amount of online content associated with that person. This not only enables identity inference but also exposes their digital footprint, such as social media activity, private photos, and news reports, often without their consent. In response to this emerging threat, we propose Protego, a user-centric privacy protection method that safeguards facial images from such retrieval-based privacy intrusions. Protego encapsulates a user's 3D facial signatures into a pose-invariant 2D representation, which is dynamically deformed into a natural-looking 3D mask tailored to the pose and expression of any facial image of the user, and applied prior to online sharing. Motivated by a critical limitation of existing methods, Protego amplifies the sensitivity of FR models so that protected images cannot be matched even among themselves. Experiments show that Protego significantly reduces retrieval accuracy across a wide range of black-box FR models and performs at least 2x better than existing methods. It also offers unprecedented visual coherence, particularly in video settings where consistency and natural appearance are essential. Overall, Protego contributes to the fight against the misuse of FR for mass surveillance and unsolicited identity tracing.
Abstract (translated)
面部识别（FR）技术日益被用于大型图像检索系统，引发了严重的隐私问题。像Clearview AI和PimEyes这样的服务允许任何人上传一张面部照片，并检索与此人相关的大量在线内容。这不仅使身份推断成为可能，还暴露了他们的数字足迹，例如社交媒体活动、私人照片和新闻报道，通常并未征得个人同意。 为了应对这一新兴威胁，我们提出了Protego，这是一种以用户为中心的隐私保护方法，旨在保护面部图像免受此类基于检索的隐私侵犯。Protego将用户的3D面部特征封装成一个与姿势无关的2D表示，并将其动态变形为一个自然外观的3D面具，该面具根据任何面部图像的姿态和表情定制并应用于在线分享之前。 鉴于现有方法的一个关键限制，Protego增强了面部识别模型的敏感性，使得即使在保护后的图像之间也无法进行匹配。实验表明，Protego显著降低了黑盒面部识别模型的检索精度，并且至少比现有的方法表现好2倍。此外，它还提供了前所未有的视觉连贯性，在视频设置中尤其重要，因为在这类场景下，一致性和自然外观至关重要。 总的来说，Protego有助于对抗滥用面部识别技术进行大规模监控和未经授权的身份追踪的行为。
URL
https://arxiv.org/abs/2508.02034
