Counting Down Thunder

Abstract

The Lightning Network is a scaling solution for Bitcoin that promises to enable rapid and private payment processing. In Lightning, multihop payments are secured by utilizing Hashed Time-Locked Contracts (HTLCs) and encrypted on the network layer by an onion routing scheme to avoid information leakage to intermediate nodes. In this work, we however show that the privacy guarantees of the Lightning Network may be subverted by an on-path adversary conducting timing attacks on the HTLC state negotiation messages. To this end, we provide estimators that enable an adversary to reduce the anonymity set and infer the likeliest payment endpoints. We developed a proof-of-concept measurement node that shows the feasibility of attaining time differences and evaluate the adversarial success in model-based network simulations. We find that controlling a small number of malicious nodes is sufficient to observe a large share of all payments, emphasizing the relevance of the on-path adversary model. Moreover, we show that adversaries of different magnitudes could employ timing-based attacks to deanonymize payment endpoints with high precision and recall. CCS CONCEPTS • Security and privacy → Distributed systems security; • Networks → Network privacy and anonymity.

On the Anonymity of Peer-To-Peer Network Anonymity Schemes Used by Cryptocurrencies

“…There exist multiple LN client implementations, such as LND [31], c-lightning [6] and eclair [16], with LND being the most widely used (more than 90% of clients [28], [45], [37]). In all these implementations, senders find paths to recipients using the Dijkstra algorithm mentioned above.…”

“…LN, however, has multiple client implementations (LND, c-lightning, and eclair) with variations in how they construct paths [52], [29]. For our analysis, we used LND's implementation, as the majority of the nodes in the LN (> 90%) use it [45], [37]. The routing algorithms of the other implementations can be easily incorporated by modifying the weight function before calculating the best paths using Dijkstra.…”

“…[42]. The exploitation of such mechanisms to deanonymize transactions has been studied in previous works [33], [22], [34], [45], [40]. Our analysis makes abstraction of transaction data and instead relies exclusively on traffic data that can be passively collected.…”

Can Lightning Network’s Autopilot Function Use BA Model as the Underlying Network?

“…Current research on the Lightning Network focuses on three aspects: topological properties [15,19,20,[23][24][25][26][27][28], security [9,14,[29][30][31][32][33][34][35], and routing methods [11,12,17,[36][37][38][39]. Although all the above studies are very important aspects of Lightning Network, they are strictly dependent on the underlying topological network.…”

“…In terms of the connection of nodes, Bertucci et al [26] investigated that the competition between nodes followed the Bertrand model 5 and pointed out that the centralized network structure must not be the optimal network structure. Rincon et al [33] classified the connections between nodes in the network into three types and evaluated the contribution of different kinds of connections to the network structure. Avarikioti et al [6] analyzed the impact of different charging mechanisms of nodes on the robustness and connectivity of the network.…”