Monero Peer-to-peer Network Topology Analysis

TL;DR

Problem: characterizing Monero's P2P network topology after protocol changes that obscure peer information. Approach: apply Nearest Neighbour Degree ($K_{nn}(k)$) and $k$-core decomposition to detect a core-periphery structure and examine core-periphery connectivity patterns. Findings: the network shows disassortative mixing with assortativity $\rho \approx -0.28$; a 4,837-node network with 14 super-nodes and a $k=16$ $k$-core consisting of 178 nodes, where super-nodes primarily connect to non-super peers; removing these super-nodes collapses much of the network's connectivity, highlighting backbone fragility. Significance: results illuminate topology-driven resilience and vulnerabilities in Monero’s auto-peering design and inform security-focused decentralization strategies.

Abstract

Monero, a privacy-focused cryptocurrency, employs a decentralized peer-to-peer (P2P) network that plays a critical role in transaction propagation and consensus formation. While much research has explored Monero's privacy transaction mechanisms, its underlying P2P network architecture has remained relatively underexplored. In this study, building on our recent work on Monero network detection, we further investigate the network topology of Monero's P2P structure, which has evolved following recent protocol updates that enhanced security by obscuring peer information. Using k-core decomposition, we confirm that the Monero network exhibits a core-periphery structure, where a tightly interconnected core of supernodes is crucial for maintaining network cohesion, while peripheral nodes rely on these core nodes for connectivity. This structure explains why targeting central nodes does not easily lead to the rapid disintegration of the network's largest connected component while also providing a deeper understanding of the true architecture of Monero's peer protocol.

Figures (4)

• Figure 1: $K_{nn}(k)$ of Monero's P2P network with assortativity -0.28.
• Figure 2: (1) Core-periphery structure of the Monero Peer-to-Peer network using the $k$-core algorithm. Nodes are reordered based on their degree. Filled cells indicate the presence of edges, while open cells denote their absence. The dotted lines mark the boundary between the core and periphery. (2) The zoomed-in Matrix plot of the core part of the Monero P2P network.
• Figure 3: The graph of the core part corresponding to Fig.\ref{['core-peri']} (2). These 14 super-peer nodes with larger sizes are located in the center. The color of a node varies with the magnitude of its degree, using the 'gist_heat' colormap. The smaller the degree, the darker the color.
• Figure 4: Scatter plot of node connectivity, where the x-axis ($k_{i}$) represents the total node degree on a logarithmic scale and the y-axis ($k\{SN\}_{i}$) indicates the number of connections each node has to the top 14 high-degree nodes. Green points denote nodes that belong to the network's k-core, while blue points represent nodes outside the k-core. Dashed red and purple lines mark the reference thresholds at $x = 8$.