区块链系统L-顽固策略的安全问题研究

Researcheson Security Issues of L-Stubborn Strategies in the Blockchain System

摘要: 随着数字货币的诞生，区块链技术被广泛的运用在金融、物联网等各个领域。但同时也暴露出各种安全性问题，如数据层的碰撞攻击、网络层的日蚀攻击、共识层的贿赂攻击、应用层的顽固攻击等。为了保障区块链技术在实际应用系统中能安全运行，研究者针对不同威胁策略，提前分析以提高系统的安全强度。本文发现基于日蚀攻击的L-顽固策略在特定情况下存在更大的安全问题。为了进一步分析这种组合式策略对区块链系统的威胁，建立了L-贿赂顽固策略(LBSM)模型。该模型在原L-顽固策略中，再考虑贿赂策略，将部分挖矿收益当作贿款吸引其他节点在私链上工作，提高私链在分支竞争中的胜率，诚实节点将会遭受更多的损失。仿真实验表明：LBSM模型造成的损失高出原L-顽固策略3.76%。最后，针对LBSM策略安全问题，提出了一些相关检测和防御措施，以提高区块链系统整体安全性。

Abstract: Since the digital currency was proposed, blockchain technology has been widely used in various fields such as finance and the Internet of Things. At the same time, various security issues have been exposed, such as collision attacks at the data layer, eclipse attacks at the network layer, brib-ery attacks at the consensus layer, and stubborn attacks at the application layer. In order to ensure the safe operation of blockchain technology in practical application systems, researchers analyze different threat strategies to improve the security of the system. In this paper, it is found that the L-stubborn strategy based on eclipse attacks has greater security risks in certain situations. In or-der to further analyze the threat of this combined strategy to the blockchain system, an L-bribery-stubborn strategy (LBSM) model was established. Under the original L-stubborn strategy, if the malicious nodes consider the bribery strategy again, using part of the mining revenue as a bribe to attract other nodes to work on the private chain and increase the winning rate of the pri-vate chain in the fork competition, honest nodes will suffer even greater damage. Simulation ex-periments show that the loss is 3.76% higher than the original L-stubborn strategy. Finally, for the security issues of the LBSM strategy, some relevant detection and defense measures have been proposed to improve the overall security of the blockchain system.