1 INTRODUCTION

2 PRELIMINARIES OF VOICE ASSISTANT APPLICATIONS
2.1 Voice Assistant Components and Speech Recognition Workflow
2.2 Speaker Identification Workflow
2.3 Metrics
2.4 Taxonomy

3 ATTACKS AND DEFENCES IN ASR-BASED VOICE ASSISTANT APPLICATIONS
3.1 Backdoor Attacks and Defences in ASR
3.2 Voice Squatting and Voice Masquerading
3.3 Adversarial Attacks and Defences in ASR
3.5 Dolphin Attack and its Defences in ASR

4 ATTACKS AND DEFENCES IN SI-BASED VOICE ASSISTANT APPLICATIONS
4.1 Attacks against SI-based Models
4.2 Defensive Methods for SI-based Models

5 PRIVACY ISSUES BEYOND TECHNICAL ATTACKS

7 CONCLUSION