Ensuring privacy in face recognition: a survey on data generation, inference and storage

As facial recognition technology plays an increasingly pivotal role in biometric authentication, its potential threats to individual privacy have raised significant societal concerns. This paper provides a survey of privacy-preserving techniques across the three critical stages of facial recognition: data generation, model inference, and data storage. We explore challenges and methodologies for safeguarding privacy within facial recognition systems, given growing concerns over biometric data misuse. In particular, we highlight the shift from traditional datasets to synthetic counterparts, leveraging generative models like GANs and diffusion models to create diverse and realistic facial imagery without compromising privacy. At the model inference stage, we discuss privacy-preserving approaches, including transformation-based methods and cryptographic techniques such as homomorphic encryption. Finally, we examine the vulnerabilities of face templates and the cryptographic protections against inversion attacks. Our survey underscores the importance of balancing recognition accuracy with privacy preservation and calls for concerted research and policy efforts to advance privacy-centric face recognition technologies that respect individual rights while maintaining operational efficacy.