Speaker verification using Secure Binary Embeddings

This paper addresses privacy concerns in voice biometrics. Conventional remote speaker verification systems rely on the system to have access to the user's recordings, or features derived from them, and also a model of the user's voice. In the proposed approach, the system has access to none of them. The supervectors extracted from the user's recordings are transformed to bit strings in a way that allows the computation of approximate distances, instead of exact ones. The key to the transformation uses a hashing scheme known as Secure Binary Embeddings. An SVM classifier with a modified kernel operates on the hashes. This allows speaker verification to be performed without exposing speaker data. Experiments showed that the secure system yielded similar results as its non-private counterpart. The approach may be extended to other types of biometric authentication.