Cryptographic key generation and data encryption and decryption using wearable biometric technologies is an emerging research area with significant potential to authentication and communication security. The research area is rapidly developing, and a comprehensive review of recent published literature is necessary to establish emerging challenges. This research article aims to critically investigate and synthesise current research using biometric cryptosystems that use behaviour or medico-chemical characteristics, ranging from gate analysis to gaze tracking. The study will summarise the state of knowledge, identify critical research gaps, and provide insight into promising future implications and applications that can enable the realisation of user-specific and resilient solutions for authentication and secure communications demands
