Private Key Encryption And Management In Blockchain With Biometrics

With the development of digital currencies such as Bitcoin,blockchain technology,as its core mechanism,has the characteristics of decentralization,reliability,data immutability,transaction anonymity,and open-source programmability.It has been researched and applied in many fields such as data sharing.However,the basic theory and technology research of blockchain is still in its infancy,and there are still problems such as security,efficiency,resources,and games that need to be studied in depth.The security issues of blockchain include data security,consensus security,privacy security,etc.,which are fundamental issues affecting the reliability of the entire system architecture.This paper mainly studies how to ensure the security of public and private key pairs.At present,blockchain applications generally lack an effective private key management mechanism.Currently,there are two main problems in the management of private keys: Firstly,the encryption of private key of the blockchain.There is no safe,reliable,and convenient way to generate the key used for encryption.Secondly,there is a lack of a systematic solution to ensure the security and reliability of the whole life of private key,such as generation,encryption,storage and recovery.In response to the first problem,this paper proposes a biometric-based stable key generation method,which uses facial features and fingerprint features to generate a stable and accurately reproducible key.This key is used for the reliable encryption if private key of the blockchain.First,existing feature extraction algorithms are used to obtain stably distributed feature points in face and fingerprint images.Then,taking advantage of the relative invariance between facial and fingerprint feature points,a stable and distinguishable descriptor calculation method based on two-dimensional feature points is proposed.Adaptively stable distinguishable descriptors.Finally,there will be slight errors between the results of multiple calculations of the stable and distinguishable descriptor,which cannot be directly used as a key.The reusable fuzzy extractor is used to operate on it to generate a stable key,which is the foundation of reliable encryption of the private key.In response to the second problem,this paper proposes a systematic blockchain private key management scheme,which realizes the secure generation,reliable encryption,distributed storage,and accurate recovery of private keys,and ensures the security and reliability of each step of private key management.In the private key security generation stage,an asymmetric key generation algorithm based on LWE(Learning with Errors)is used to ensure the security of asymmetric keys against quantum computing attacks.In the stage of reliable private key encryption,the generated private key is secretly split using the secret-sharing technology based on the Chinese remainder theorem,and the secret fragments obtained after splitting are encrypted using the private key encryption algorithm based on multiple biometric keys.In the distributed storage stage of encrypted secret pieces,the blockchain system realize the safe,reliable,and distributed storage of encrypted secret fragments by itself.In the stage of accurate private key recovery,the private key can be reliably recovered after the general steps of accurate private key recovery proposed in this paper.This paper analyzes the quality of the feature points extracted from faces and fingerprints and retains enough stable and distinguishable feature points to extract descriptors.Statistical analysis was carried out on the errors existing in the calculation of descriptors at different times,and the experiments verified the controllability of the descriptor errors of the same organism in different periods.The key obtained by fuzzy extraction based on biometric descriptors is analyzed,and its accuracy and efficiency are verified by experiments.The experiment analyzes the validity and accuracy of private key encryption based on the biometric key and analyzes the validity of the secret-sharing algorithm based on the Chinese remainder theorem.To verify the efficiency,effectiveness,and accuracy of the algorithm proposed in this paper,this paper builds a blockchain system based on Ethereum and conducts systematic experiments to confirm the feasibility of generating a stable and unique key based on biometrics and reliability of the private key management scheme.