A Blockchain-Based Biometric Template Revocation System using Quantum-Safe Encryption and Decentralized Storage

Contemporary biometric access control systems face significant security challenges due to the irreversible nature of biometric data, the growing threat of quantum computing to classical encryption, and the risks of centralized data storage. This underscores the need for a new paradigm for secure biometric authentication, focusing more on the storage, encryption, and revocation of the biometric data. To this end, this paper proposes a new comprehensive scheme that integrates blockchain technology, the InterPlanetary File System (IPFS), and the lattice-based cryptography through BGV fully homomorphic encryption scheme to establish a secure, transparent, user-centric protocol for biometric template revocation and re-enrollment. The proposed framework empowers users to proactively initiate a revocation procedure when they suspect template compromise, by creating a new, cryptographically unique template version from the original biometric data using a secure transformation API through transformation parameters, and safely saves them in a decentralized fashion on IPFS. The compromised template is methodically invalidated on the immutable blockchain ledger, while a set of smart contracts ensure decentralized access control management. Moreover, Lattice-based Cryptography mechanisms through the BGV scheme is used to encrypt the biometric template and transformation parameters before storage process upon IPFS, which protects the system from quantum computing attacks. The experiments have demonstrated the effectiveness of our solution by achieving an EER of 1.23%, providing quantum-resistant security, and ensuring tamper-evident auditability via blockchain, which provide a robust, scalable, and privacy-preserving scheme for blockchain-based biometric access control systems.