Evasion and obfuscation in speaker recognition surveillance and forensics

This paper presents the first investigation of evasion and obfuscation in the context of speaker recognition surveillance and forensics. In contrast to spoofing, which aims to provoke false acceptances in authentication applications, evasion and obfuscation target detection and recognition modules in order to provoke missed detections. The paper presents our analysis of each vulnerability and the potential for countermeasures using standard NIST datasets and protocols and six different speaker recognition systems (from a standard GMM-UBM system to a state-of-the-art i-vector system). Results show that all systems are vulnerable to both evasion and obfuscation attacks and that a new generalised countermeasure shows promising detection performance. While all evasion attacks and almost all obfuscation attacks are detected in the case of this particular setup, the work nonetheless highlights the need for further research.