SPDL: Blockchain-secured and Privacy-preserving Decentralized Learning

Abstract

Decentralized learning involves training machine learning models over remote mobile devices, edge servers, or cloud servers while keeping data localized. Even though many studies have shown the feasibility of preserving privacy, enhancing training performance or introducing Byzantine resilience, but none of them simultaneously considers all of them. Therefore we face the following problem: how can we efficiently coordinate the decentralized learning process while simultaneously maintaining learning security and data privacy? To address this issue, in this paper we propose SPDL, a blockchain-secured and privacy-preserving decentralized learning scheme. SPDL integrates blockchain, Byzantine Fault-Tolerant (BFT) consensus, BFT Gradients Aggregation Rule (GAR), and differential privacy seamlessly into one system, ensuring efficient machine learning while maintaining data privacy, Byzantine fault tolerance, transparency, and traceability. To validate our scheme, we provide rigorous analysis on convergence and regret in the presence of Byzantine nodes. We also build a SPDL prototype and conduct extensive experiments to demonstrate that SPDL is effective and efficient with strong security and privacy guarantees.

A Blockchain-Based Federated-Learning Framework for Defense against Backdoor Attacks

“…However, in the comparative experiment, to test the effectiveness of backdoor attacks, we set the probability parameters T and waiting time (T w , T m ) always to be online and infinite waiting. [16,17] The gradient aggregation rule (GAR) aggregates gradients received from peers during each round. We designed the GAR to add robustness to the gradient generated by malicious participants who use backdoor attacks.…”

“…The PoSA blockchain consensus process deeply integrates the blockchain, PoSA consensus protocol [20], and GAR [16] aggregation functions. Specifically, the blockchain consensus includes two parts: an equity calculation and the choice of winners among the miners.…”

Sea Shield: A Blockchain Technology Consensus to Improve Proof-of-Stake-Based Consensus Blockchain Safety

“…Blockchain is a new technology that saves data in a decentralized manner. Blockchain technology plays a significant role in improving many systems such as cryptocurrency [1], supply chain [2], e-voting [3], Metallurgical and Machine-building tasks [4], autonomous decentralized online social networks [5], health care [6], and Privacy-preserving decentralized learning [7]. The core feature of this technology is to save data by creating timestamp blocks in peer-to-peer networks.…”