Abstract
Bitcoin (BTC) pseudonyms (layer 1) can effectively be deanonymized using heuristic clustering techniques. However, while performing transactions off-chain (layer 2) in the Lightning Network (LN) seems to enhance privacy, a systematic analysis of the anonymity and privacy leakages due to the interaction between the two layers is missing. We present (Please, find the full version of this paper with appendix at https://arxiv.org/abs/2007.00764.) clustering heuristics that group BTC addresses, based on their interaction with the LN, as well as LN nodes, based on shared naming and hosting information. We also present linking heuristics that link \(45.97\)% of all LN nodes to \(29.61\)% BTC addresses interacting with the LN. These links allow us to attribute information (e.g., aliases, IP addresses) to \(21.19\)% of the BTC addresses contributing to their deanonymization. Further, these deanonymization results suggest that the security and privacy of LN payments are weaker than commonly believed, with LN users being at the mercy of as few as five actors that control 36 nodes and over \(33\%\) of the total capacity. Overall, this is the first paper to present a method for linking LN nodes with BTC addresses across layers and to discuss privacy and security implications.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
The proprietary attribution data from Chainalysis is not included in the published dataset. The reader can contact the company for further inquiry.
- 2.
Although theoretically a payment channel can be dual-funded (i.e., Bob also contributes \(x _1\) to the funding transaction), this feature is under discussion in the community [3] and currently only single-funded channels are implemented in practice.
- 3.
- 4.
- 5.
Some channels were opened with the same funding transaction.
- 6.
- 7.
- 8.
- 9.
We note that this requirement may no longer be there if the “fund-from-external-wallet” functionality, already available in the recent release [19], is widely adopted.
- 10.
Here we do not consider source and destination entities as they do not directly interact with the LN.
- 11.
We note that Chainalysis attribution data is not strictly necessary for the linking algorithms.
References
Hash time locked contracts. Wiki post. https://en.bitcoin.it/wiki/Hash_Time_Locked_Contracts
Community, L.N.: Bitcoin transaction and script formats. https://github.com/lightningnetwork/lightning-rfc/blob/master/03-transactions.md
Community, L.N.: Wip: dual funding (v2 channel establishment protocol). Github Issue. https://github.com/lightningnetwork/lightning-rfc/pull/524
Decker, C.: Privacy in lightning. Blog post (2018). https://snyke.net/post/privacy-in-lightning/
Decker, L.N.C.: New release: c-lightning 0.7.1. Blostream Blog Post. https://medium.com/blockstream/new-release-c-lightning-0-7-1-9fca65debeb2
Gudgeon, L., Moreno-Sanchez, P., Roos, S., McCorry, P., Gervais, A.: SoK: layer-two blockchain protocols. In: Bonneau, J., Heninger, N. (eds.) FC 2020. LNCS, vol. 12059, pp. 201–226. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-51280-4_12
Harrigan, M., Fretter, C.: The unreasonable effectiveness of address clustering. In: Conferences on Ubiquitous Intelligence & Computing, Advanced and Trusted Computing, Scalable Computing and Communications, Cloud and Big Data Computing, Internet of People, and Smart World Congress (UIC/ATC/ScalCom/CBDCom/IoP/SmartWorld) (2016)
Jian-Hong, L., Kevin, P., Tiziano, S., Christian, D., J, T.C.: Lightning network: a second path towards centralisation of the bitcoin economy (2020). https://arxiv.org/abs/2002.02819
Jourenko, M., Kurazumi, K., Larangeira, M., Tanaka, K.: SoK: A Taxonomy for Layer-2 Scalability Related Protocols for Cryptocurrencies. Cryptology ePrint Archive, Report 2019/352 (2019). https://eprint.iacr.org/2019/352
Kalodner, H., Goldfeder, S., Chator, A., Möser, M., Narayanan, A.: BlockSci: design and applications of a blockchain analysis platform (2017). https://arxiv.org/abs/
Kappos, G., et al.: An empirical analysis of privacy in the lightning network (2020). https://arxiv.org/abs/2003.12470
Kus Khalilov, M.C., Levi, A.: A survey on anonymity and privacy in bitcoin-like digital cash systems. Commun. Surv. Tutor. 20(3), 2543–2585 (2018)
Martinazzi, S., Flori, A.: The evolving topology of the lightning network: centralization, efficiency, robustness, synchronization, and anonymity. PLOS ONE 15(1), 1–18 (2020)
Meiklejohn, S., et al.: A fistful of bitcoins: characterizing payments among men with no names. In: Internet Measurement Conference (2013)
Nowostawski, M., Jardar, T.: Evaluating methods for the identification of off-chain transactions in the lightning network. Appl. Sci. 9(12), 2519 (2019)
Poon, J., Dryja, T.: The Bitcoin Lightning Network (2016). http://lightning.network/
Rohrer, E., Malliaris, J., Tschorsch, F.: Discharged payment channels: quantifying the lightning network’s resilience to topology-based attacks. In: European Symposium on Security and Privacy Workshops (2019)
Seres, I.A., Gulyás, L., Nagy, D.A., Burcsi, P.: Topological analysis of bitcoin’s lightning network. In: Pardalos, P., Kotsireas, I., Guo, Y., Knottenbelt, W. (eds.) Mathematical Research for Blockchain Economy. SPBE, pp. 1–12. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-37110-4_1
Vu, B.: Announcing lnd v0.10-beta! Lightning Labs Blog Post. https://lightning.engineering/posts/2020-04-30-lnd-v0.10/
Acknowledgments
This work is partially funded by the European Research Council (ERC) under the European Unions Horizon 2020 research (grant agreement No 771527-BROWSEC), by PROFET (grant agreement P31621), by the Austrian Research Promotion Agency through the Bridge-1 project PR4DLT (grant agreement 13808694); by COMET K1 SBA, ABC, by CoBloX Labs, by the Austrian Science Fund (FWF) through the Meitner program (project agreement M 2608-G27) and by the Austrian security research programme KIRAS of the Federal Ministry of Agriculture, Regions and Tourism (BMLRT) under the project KRYPTOMONITOR (879686). The authors would also like to thank Peter Holzer and Marcel Müller for setting up and starting the LN data collection process.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2021 International Financial Cryptography Association
About this paper
Cite this paper
Romiti, M., Victor, F., Moreno-Sanchez, P., Nordholt, P.S., Haslhofer, B., Maffei, M. (2021). Cross-Layer Deanonymization Methods in the Lightning Protocol. In: Borisov, N., Diaz, C. (eds) Financial Cryptography and Data Security. FC 2021. Lecture Notes in Computer Science(), vol 12674. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-64322-8_9
Download citation
DOI: https://doi.org/10.1007/978-3-662-64322-8_9
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-64321-1
Online ISBN: 978-3-662-64322-8
eBook Packages: Computer ScienceComputer Science (R0)