g4tt0's avatar
g4tt0 1 year ago
Run #LND? get a #TOR running partner #lightning #privacy #research Payment Censorship in the Lightning Network Despite Encrypted Communication - Charmaine Ndolo & Florian Tschorsch, 2024 "5.2 Towards a solution ... The purpose of doing so is to utilise Tor’s implementation of WTF-PAD and not for Tor’s privacy properties. We issued payments in both directions, closed the channel and finally the TCP connection. Not only did all packets have the same packet length (as is expected when using Tor), but the flow of transmitted packets included packets that did not originate from the application. Consequently, we were not able to detect which packets belonged to which Lightning message by manually inspecting the capture. The rule-based state machine is therefore no longer capable of distinguishing application messages based on the network traces alone. In fact, we conjecture that this approach offers a high degree of protection for the LN against more sophisticated fingerprinting techniques by network-level adversaries as basically all size and timing features are destroyed. ... Specifically, we concurrently captured the packets sent locally between the LND node and the Tor SOCKS5 proxy, as well as the packets sent between the Tor process and Tor network. The former provides data on the packets that actually come from the application while the latter provides data on what a network-level attacker would observe. The captures show a total of 14, 824 bytes transmitted in 379 TCP packets to/from LND and 929, 596 bytes in 3191 TCP packets to/from the Tor network. This equates to an increase of ≈ 6170% in bandwidth when using Tor. The captures also show a peak rate of 0.116 Mbit/s when using Tor, which clearly should not cause any problems for LN nodes while maintaining their current hardware configurations."
calle's avatar calle
Payment Censorship in the Lightning Network Despite Encrypted Communication The authors demonstrate how to detect LN messages by their deterministic sizes and packet flows. These methods allow a network-level adversary to identify and censor payments in the Lightning Network. 😱 image Paper: https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2024.12
View quoted note →

Replies (1)

g4tt0's avatar
g4tt0 1 year ago
respect to the researcher's ethics "2.4 Ethical Considerations As far as the practical evaluation of the presented attack is concerned, we followed the guidelines of the Menlo report [5] and general security research best practices. In particular, with the exception of obtaining a network snapshot from our own node, we did not interact with the public mainnet in any way. We deployed a modified version of our proof-of-concept implementation to the testnet in order to validate the feasibility of the attack’s preliminary phase. However, at no point did we actually mount the attack in the testnet. All adverse experiments were conducted in our private network comprising only nodes we set up for the precise purpose. In order to evaluate the potential impact of our work on the main network, we followed a simulation-based approach using the obtained snapshot. The simulation mocks payment routing in the network by reconstructing the topology locally."