The Design and Implementation of Blockchain-Assisted User Public-Private Key Generation Method

The rapid development of network technology has brought new challenges to data security. As the first gateway of a certain mobile internet system, access authentication is an essential step that guarantees the internal security of the network. However, there are some problems in traditional cryptosystem-based authentication mechanisms, such as certificate management problem and centralized key escrow problem. Centralized storage of user information is restricted by the server, the security of the server is not within the user’s control, the stability of the server cannot be guaranteed, and personal privacy on the server may be leaked. In this paper, we focus on the private key escrow problem caused by the Private Key Generator (PKG) in Identity-Based Cryptosystems (IBC) mechanism and propose a Blockchain-assisted user public-private key generation scheme (BAKG) which introduces the blockchain to improve the robustness and reliability of key management. In BAKG, the user’s private key is determined by itself through combining the partial private keys from different PKGs, which prevents the risk of private key exposure caused by a single PKG. Meanwhile, based on the theory of the Combined Public Key (CPK) algorithm, we have designed a feasible blockchain-based key generation logic and developed a prototype authentication system based on the above concept. We further analyze the security of BAKG and the analytical results show that BAKG can meet various security requirements. In addition, according to the performance evaluation results, BAKG has good performance in both read/write consensus and different key length calculations, which means it has good potential for lightweight authentication applications.