Secure and Efficient Key Hierarchical Management and Collaborative Signature Schemes of Blockchain.

As the core of the blockchain, reliable key management is the necessary guarantee for the security of the blockchain business. However, existing key management methods of blockchain mainly include local storage, offline storage, and wallet storage, and cannot meet the requirements of security, ease of use, and cost at the same time. Moreover, the key management scheme of the blockchain itself lacks a secure and efficient solution to manage the user’s key. In addition, the situation of collaborative signatures should be considered in the blockchain to meet the needs of users. To this end, secure multi-party computation (SMPC) is the most used technology, and the security of these schemes can be further improved. In order to improve the security and efficiency of blockchain key management and meet the needs of collaborative work, key hierarchical management and collaborative signature schemes incorporating SMPC and feature encryption are proposed. In this scheme, the keys are divided into three layers, and the keys of the upper layer are used to encrypt the keys of the lower layer, thus ensuring the security of all keys. Moreover, the processes of key generation, recovery, revocation and update, and multi-party signature are designed in detail. Compared with other schemes through theory analysis and experiment, our schemes can reduce the file-sharing time and the storage overhead of the user. This can improve the utilization of system resources and system efficiency, while ensuring a high level of security.