Privacy and Security Issues in Speech Processing

As the use of speech as a modality of interacting with devices becomes more popular, a natural question arises -- can these systems be trusted? In addition to the many usual requirements of trustworthiness such as accuracy, reliability, fairness, security, etc., speech systems face unique challenges relating to privacy. Speech carries a lot more information than the mere content of what was spoken -- it also carries information about the speakers themselves, including their gender, nationality and native language, emotional state, health, and a variety of other biometric and demographic information. In the process of using the speech service, users expose themselves to unintended exploitation of this information. The privacy risks associated with the use of speech based interaces is now increasingly recognized by governments and corporate institutions alike.In this talk we will discuss the privacy-related challenges of the use of speech as a biometric signal, and the need for protection. We will discuss the legal landscape of the problem, and introduce the various solutions that have been proposed, including cryptographic, multi-party-computation based, and hashing-based solutions, and their limitations.Finally, time permitting we will briefly also discuss more recent methods based on adversarial processing of speech, and how these solutions may in fact serendipitously address some of the other aspects of trustworthiness of speech-processing.