Biometric reliant system and method

A biometric authentication device for secure decentralized communication, comprising:

• a card body comprising a core layer including a substrate film, an antenna structure disposed on or at least partially embedded within the substrate film and configured to generate energy through induction in an electromagnetic field, a system-in-package comprising at least one chip disposed on or embedded within the substrate film and electrically connected with the antenna structure, and a crosslinked polymer composition disposed on both sides of the substrate film;
• a capacitive fingerprint reader integrated into a surface of the card body and configured to capture fingerprint data from a user;
• a cryptographic processor electrically connected to the system-in-package and configured to:
• receive extracted features from the captured fingerprint data,
• combine the extracted features with a user-specific salt via a secure one-way hashing function,
• apply error correction using helper data comprising parity bits stored on the device to regenerate a cryptographic private key from the captured fingerprint data without retrieving a stored static key, the cryptographic private key existing only transiently in device memory, and
• sign a transaction request using the regenerated cryptographic private key;
• and
• a communication interface configured to transmit the signed transaction request to a private blockchain ledger for authentication and to derive session keys for encrypted communications recorded as hashes on the private blockchain ledger for trust verification among network participants.

A method for secure communication using a biometric blockchain card having a layered core embedding a biometric sensor module, a processor, and a communication interface, the method comprising:

• capturing a fresh biometric sample from a user using the biometric sensor module for each authentication session;
• extracting features from the fresh biometric sample to produce a feature vector;
• transforming the feature vector through hashing with a user-specific salt generated during enrollment and stored in tamper-resistant memory on the card;
• applying error correction to the transformed feature vector using helper data comprising non-sensitive parity bits stored on the card to regenerate a cryptographic private key, the cryptographic private key derived from the fresh biometric sample and existing only transiently in device memory during the authentication session such that no static private key is persistently stored on the card;
• authenticating to a private blockchain ledger by signing a challenge using the regenerated cryptographic private key;
• transmitting a join request via the communication interface, the join request validated by a consensus mechanism to register the user on the private blockchain ledger;
• and
• deriving session keys for encrypted communications, the encrypted communications recorded as hashes on the private blockchain ledger to verify trust among network participants.