14thAnnual Conference of the International Speech Communication Association

Lyon, France
August 25-29, 2013

Secure Binary Embeddings of Front-End Factor Analysis for Privacy Preserving Speaker Verification

José Portêlo (1), Alberto Abad (1), Bhiksha Raj (2), Isabel Trancoso (1)

(1) INESC-ID Lisboa, Portugal
(2) Carnegie Mellon University, USA

Remote speaker verification services typically rely on the system to have access to the users recordings, or features derived from them, and also a model of the users voice. This conventional scheme raises several privacy concerns. In this work, we address this privacy problem in the context of a speaker verification system using a factor analysis based front-end extractor, the so-called i-vectors. Speaker verification without exposing speaker data is achieved by transforming speaker i-vectors 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. Then, a modified SVM kernel permits operating on the i-vector hashes. Experiments on sub-sets of NIST SRE 2008 showed that the secure system yielded similar results as its non-private counterpart.

Full Paper

Bibliographic reference.  Portêlo, José / Abad, Alberto / Raj, Bhiksha / Trancoso, Isabel (2013): "Secure binary embeddings of front-end factor analysis for privacy preserving speaker verification", In INTERSPEECH-2013, 2494-2498.