论文标题
使用中心点的弹性分布式向量共识
Resilient Distributed Vector Consensus Using Centerpoints
论文作者
论文摘要
在本文中,我们研究了具有对抗药物的网络中的弹性矢量共识问题,并提高了现有算法的弹性保证。实现弹性矢量共识的一种常见方法是,网络中的每个非对抗性(或正常)代理都通过向其\ emph {normal}邻居状态的凸面中的一个点移动来更新其状态。由于代理无法区分其正常邻居和对抗性邻居,因此计算这样的观点(通常称为\ emph {safe Point})是一项具有挑战性的任务。为了计算一个安全点,我们建议使用\ emph {centerpoint}的概念,这是中位数在较高维度中的扩展,而不是点的分区,这通常用于此目的。我们讨论了CenterPoint的概念提供了$ \ Mathbb {r}^d $中安全点的完整表征。特别是,如果在普通代理$ i $附近的对手的数量小于$ \ frac {n_i} {d+1} $,则安全点本质上是一个内部中心点,其中$ d $是国家向量和$ n_i $的维度。因此,我们获得了对对抗剂数量的必要条件,以保证有弹性载体共识。此外,通过考虑计算中心点的复杂性,我们讨论了向量共识算法的弹性保证的改进,并与其他现有方法进行比较。最后,我们通过实验来数字评估方法的性能。
In this paper, we study the resilient vector consensus problem in networks with adversarial agents and improve resilience guarantees of existing algorithms. A common approach to achieving resilient vector consensus is that every non-adversarial (or normal) agent in the network updates its state by moving towards a point in the convex hull of its \emph{normal} neighbors' states. Since an agent cannot distinguish between its normal and adversarial neighbors, computing such a point, often called as \emph{safe point}, is a challenging task. To compute a safe point, we propose to use the notion of \emph{centerpoint}, which is an extension of the median in higher dimensions, instead of Tverberg partition of points, which is often used for this purpose. We discuss that the notion of centerpoint provides a complete characterization of safe points in $\mathbb{R}^d$. In particular, we show that a safe point is essentially an interior centerpoint if the number of adversaries in the neighborhood of a normal agent $i$ is less than $\frac{N_i}{d+1} $, where $d$ is the dimension of the state vector and $N_i$ is the total number of agents in the neighborhood of $i$. Consequently, we obtain necessary and sufficient conditions on the number of adversarial agents to guarantee resilient vector consensus. Further, by considering the complexity of computing centerpoints, we discuss improvements in the resilience guarantees of vector consensus algorithms and compare with the other existing approaches. Finally, we numerically evaluate the performance of our approach through experiments.