Direct Acyclic Graph-Based Ledger for Internet of Things: Performance and Security Analysis
Direct Acyclic Graph-Based Ledger for Internet of Things: Performance and Security Analysis
复制标题
基于直接非循环图的物联网账本：性能和安全性分析
DOI：
10.1109/tnet.2020.2991994
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Yu Jihong
中科院分区：
文献类型：
--
作者：
Li Yixin;Cao Bin;Peng Mugen;Zhang Long;Zhang Lei;Feng Daquan;Yu Jihong
基于直接无环图（DAG）的分类帐和相应的共识算法已被确定为物联网（IoT）的一种有前途的技术。与区块链中已经广泛使用的工作量证明（PoW）和权益证明（PoS）相比，设计在DAG结构上的共识机制（简称DAG共识）可以克服资源消耗高、交易费用高、交易吞吐量低、确认延迟长等缺点。然而，对DAG共识的理论分析是一个有待探索的领域。为此，基于最典型的DAG共识之一Tangle，我们研究了网络负载对基于DAG的账本的性能和安全性的影响。考虑到网络负载的不稳定性，我们首先提出了一个马尔可夫链模型来捕捉动态负载条件下的DAG共识过程的行为。关键绩效指标，即，基于所提出的模型，分析了累积权重和确认延迟。然后，我们利用一个随机模型来分析一个成功的双重支出攻击在不同的网络负载制度的概率。结果可以提供对DAG共识过程的深入理解，例如，网络负载如何影响确认延迟和成功攻击的概率。同时，我们还展示了安全级别和确认延迟之间的权衡，这可以作为基于DAG的账本的实际部署的指导。
Direct Acyclic Graph (DAG)-based ledger and the corresponding consensus algorithm has been identified as a promising technology for Internet of Things (IoT). Compared with Proof-of-Work (PoW) and Proof-of-Stake (PoS) that have been widely used in blockchain, the consensus mechanism designed on DAG structure (simply called as DAG consensus) can overcome some shortcomings such as high resource consumption, high transaction fee, low transaction throughput and long confirmation delay. However, the theoretic analysis on the DAG consensus is an untapped venue to be explored. To this end, based on one of the most typical DAG consensuses, Tangle, we investigate the impact of network load on the performance and security of the DAG-based ledger. Considering unsteady network load, we first propose a Markov chain model to capture the behavior of DAG consensus process under dynamic load conditions. The key performance metrics, i.e., cumulative weight and confirmation delay are analysed based on the proposed model. Then, we leverage a stochastic model to analyse the probability of a successful double-spending attack in different network load regimes. The results can provide an insightful understanding of DAG consensus process, e.g., how the network load affects the confirmation delay and the probability of a successful attack. Meanwhile, we also demonstrate the trade-off between security level and confirmation delay, which can act as a guidance for practical deployment of DAG-based ledgers.