Chaff-Free Fuzzy Vault using Multimodal Biometrics for Secure Key Access

Cryptography provides a strong and reliable method to secure sensitive data; however, securing cryptographic keys remains a primary challenge. One of the promising solutions to enable user-only access to their cryptographic key is to bind the key with their biometric data using a fuzzy vault scheme. Since the biometric traits are inherently limited and immutable, it is challenging to facilitate the user to regenerate the key by providing their biometric data while making it difficult for an attacker to recover the key, particularly in the event of a database breach. To address this, the existing fuzzy vault schemes utilise additional (chaff) points to obscure the genuine points. However, in such schemes, multiple vaults generated using the same biometric data remain correlated, making them susceptible to recovery of the genuine points and the corresponding key.