Frontiers of Data and Computing ›› 2022, Vol. 4 ›› Issue (6): 105-117.

CSTR: 32002.14.jfdc.CN10-1649/TP.2022.06.010

doi: 10.11871/jfdc.issn.2096-742X.2022.06.010

• Technology and Application • Previous Articles     Next Articles

An Improved BMUF Training Framework and Implementation of Federated Learning System

ZHAO Xinbo1,2(),DAI Chuangchuang1,2,LU Zhonghua1,*()   

  1. 1. Computer Network Information Center, Chinese Academy of Sciences, Beijing 100083, China
    2. University of Chinese Academy of Sciences, University, Beijing 100049, China
  • Received:2021-12-21 Online:2022-12-20 Published:2022-12-20
  • Contact: LU Zhonghua E-mail:zhaoxinbo@cnic.cn;zhlu@cnic.cn

Abstract:

[Objective] In the increasingly severe condition of privacy protection, federated learning is often used to solve problems such as "data islands" and "data privacy". However, the traditional federated learning architecture is limited by its centralized characteristic, which brings additional privacy risks and costs. The blockchain-based decentralized federated learning architecture has received more attention and research efforts due to its obvious advantages in application. [Methods] This paper improves the BMUF training framework to make better results in the scenarios of unbalanced and non-IID data distributions in federated learning. The differential privacy mechanism is added to the client's local training to protect local privacy. A byzantine detection and robust aggregation algorithm based on the global model update is proposed, which enables the aggregator to detect the byzantine clients in the system and complete the robust aggregation. [Results] Multiple experiments are conducted on the above three points. The experimental results show that the improved BMUF training framework has a better aggregation effect than the FedAvg algorithm in unbalanced and non-IID distribution scenarios. When the differential privacy mechanism is added to the client's local training, the model can still converge and obtain a higher accuracy rate. In the byzantine attack environment, the aggregator can effectively eliminate the byzantine clients and complete the robust aggregation. [Conclusions] This paper improves the BMUF training framework and implements a blockchain-based federated learning system that can effectively protect the local privacy of the client, resist byzantine attacks, and achieve efficient training of the model for different data distribution scenarios under a decentralized architecture.

Key words: blockchain, federated learning, BMUF framework, differential privacy, byzantine attack