Abstract
Payment channel networks (PCNs) are viewed as one of the most promising scalability solutions for cryptocurrencies today. Roughly, PCNs are networks where each node represents a user and each directed, weighted edge represents funds escrowed on a blockchain; these funds can be transacted only between the endpoints of the edge. Users efficiently transmit funds from node A to B by relaying them over a path connecting A to B, as long as each edge in the path contains enough balance (escrowed funds) to support the transaction. Whenever a transaction succeeds, the edge weights are updated accordingly. In deployed PCNs, channel balances (i.e., edge weights) are not revealed to users for privacy reasons; users know only the initial weights at time 0. Hence, when routing transactions, users typically first guess a path, then check if it supports the transaction. This guess-and-check process dramatically reduces the success rate of transactions. At the other extreme, knowing full channel balances can give substantial improvements in transaction success rate at the expense of privacy. In this work, we ask whether a network can reveal noisy channel balances to trade off privacy for utility. We show fundamental limits on such a tradeoff, and propose noise mechanisms that achieve the fundamental limit for a general class of graph topologies. Our results suggest that in practice, PCNs should operate either in the low-privacy or low-utility regime; it is not possible to get large gains in utility by giving up a little privacy, or large gains in privacy by sacrificing a little utility.
- Lightning network daemon. https://github.com/lightningnetwork/lnd.Google Scholar
- Raiden network. https://raiden.network/.Google Scholar
- Alessandro Acquisti, Leslie K John, and George Loewenstein. What is privacy worth? The Journal of Legal Studies, 42(2):249--274, 2013.Google Scholar
Cross Ref
- Billy Bambrough. Bitcoin just crossed a huge adoption milestone. Forbes, 2019.Google Scholar
- Alastair R Beresford, Dorothea Kübler, and Sören Preibusch. Unwillingness to pay for privacy: A field experiment. Economics letters, 117(1):25--27, 2012.Google Scholar
Cross Ref
- Srdjan Capkun, Jean-Pierre Hubaux, and Markus Jakobsson. Secure and privacy-preserving communication in hybrid ad hoc networks. Technical report, 2004.Google Scholar
- David Chaum. The dining cryptographers problem: Unconditional sender and recipient untraceability. Journal of cryptology, 1(1):65--75, 1988.Google Scholar
Digital Library
- William H Cunningham. Optimal attack and reinforcement of a network. Journal of the ACM (JACM), 32(3):549--561, 1985.Google Scholar
- Roger Dingledine, Nick Mathewson, and Paul Syverson. Tor: The second-generation onion router. Technical report, Naval Research Lab Washington DC, 2004.Google Scholar
- Mo Dong, Qingkai Liang, Xiaozhou Li, and Junda Liu. Celer network: Bring internet scale to every blockchain. arXiv preprint arXiv:1810.00037, 2018.Google Scholar
- Cynthia Dwork. Differential privacy. Encyclopedia of Cryptography and Security, pages 338--340, 2011.Google Scholar
Cross Ref
- Mine Su Erturk and Kuang Xu. Dynamically protecting privacy, under uncertainty. arXiv preprint arXiv:1911.08875, 2019.Google Scholar
- Ittay Eyal, Adem Efe Gencer, Emin Gün Sirer, and Robbert Van Renesse. Bitcoin-ng: A scalable blockchain protocol. In 13th $$USENIX$$ Symposium on Networked Systems Design and Implementation ($$NSDI$$ 16), pages 45--59, 2016.Google Scholar
- Giulia Fanti, Peter Kairouz, Sewoong Oh, Kannan Ramchandran, and Pramod Viswanath. Hiding the rumor source. IEEE Transactions on Information Theory, 63(10):6679--6713, 2017.Google Scholar
Digital Library
- Giulia Fanti, Peter Kairouz, Sewoong Oh, and Pramod Viswanath. Spy vs. spy: Rumor source obfuscation. In Proceedings of the 2015 ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems, pages 271--284, 2015.Google Scholar
Digital Library
- David Floyd. Lightning network: What is it and can it solve bitcoin's scaling problem? Investopedia, March 2018.Google Scholar
- Michael J Freedman and Robert Morris. Tarzan: A peer-to-peer anonymizing network layer. In Proceedings of the 9th ACM conference on Computer and communications security, pages 193--206. ACM, 2002.Google Scholar
Digital Library
- Julio Gil-Pulgar. Atomic Multi-Path to help Bitcoin become a formidable payment instrument. Bitcoinist, February 2018.Google Scholar
- Sharad Goel, Mark Robson, Milo Polte, and Emin Sirer. Herbivore: A scalable and efficient protocol for anonymous communication. Technical report, Cornell University, 2003.Google Scholar
- Assane Gueye, Jean C Walrand, and Venkat Anantharam. Design of network topology in an adversarial environment. In International Conference on Decision and Game Theory for Security, pages 1--20. Springer, 2010.Google Scholar
Digital Library
- Assane Gueye, Jean C Walrand, and Venkat Anantharam. A network topology design game: How to choose communication links in an adversarial environment. In Proc. of the 2nd international icst conference on game theory for networks, gamenets, volume 11, page 5, 2011.Google Scholar
- Peter Kairouz, Sewoong Oh, and Pramod Viswanath. Extremal mechanisms for local differential privacy. In Advances in neural information processing systems, pages 2879--2887, 2014.Google Scholar
Digital Library
- Rami Khalil and Arthur Gervais. Revive: Rebalancing off-blockchain payment networks. In Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security, pages 439--453. ACM, 2017.Google Scholar
Digital Library
- Giulio Malavolta, Pedro Moreno-Sanchez, Aniket Kate, and Matteo Maffei. Silentwhispers: Enforcing security and privacy in decentralized credit networks. In NDSS, 2017.Google Scholar
Cross Ref
- Giulio Malavolta, Pedro Moreno-Sanchez, Aniket Kate, Matteo Maffei, and Srivatsan Ravi. Concurrency and privacy with payment-channel networks. In Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security, pages 455--471. ACM, 2017.Google Scholar
Digital Library
- Animesh Nandi, Armen Aghasaryan, and Makram Bouzid. P3: A privacy preserving personalization middleware for recommendation-based services. In Hot Topics in Privacy Enhancing Technologies Symposium, 2011.Google Scholar
- Dmytro Piatkivskyi and Mariusz Nowostawski. Split payments in payment networks. In Data Privacy Management, Cryptocurrencies and Blockchain Technology, pages 67--75. Springer, 2018.Google Scholar
- Joseph Poon and Thaddeus Dryja. The bitcoin lightning network: Scalable off-chain instant payments, 2016.Google Scholar
- Michael K Reiter and Aviel D Rubin. Anonymous web transactions with crowds. Communications of the ACM, 42(2):32--48, 1999.Google Scholar
Digital Library
- Stefanie Roos, Pedro Moreno-Sanchez, Aniket Kate, and Ian Goldberg. Settling payments fast and private: Efficient decentralized routing for path-based transactions. arXiv preprint arXiv:1709.05748, 2017.Google Scholar
- Rob Sherwood, Bobby Bhattacharjee, and Aravind Srinivasan. P5: A protocol for scalable anonymous communication. Journal of Computer Security, 13(6):839--876, 2005.Google Scholar
Digital Library
- Vibhaalakshmi Sivaraman, Shaileshh Bojja Venkatakrishnan, Mohammad Alizadeh, Giulia Fanti, and Pramod Viswanath. Routing cryptocurrency with the spider network. In HotNets, 2019.Google Scholar
- Vibhaalakshmi Sivaraman, Shaileshh Bojja Venkatakrishnan, Kathleen Ruan, Parimarjan Negi, Lei Yang, Radhika Mittal, Giulia Fanti, and Mohammad Alizadeh. High throughput cryptocurrency routing in payment channel networks. In NSDI, 2020.Google Scholar
- Kyle Torpey. Greg maxwell: Lightning network better than sidechains for scaling bitcoin. Bitcoin Magazine, April 2016.Google Scholar
- Manny Trillo. Stress test prepares visanet for the most wonderful time of the year. http: stress-test-prepares-visanet-for-the-most-wonderful-time-of-the-year/ //www.visa.com/blogarchives/us/2013/10/10/ index.html, 2013.Google Scholar
- John N Tsitsiklis and Kuang Xu. Delay-predictability trade-offs in reaching a secret goal. Operations Research, 66(2):587--596, 2018.Google Scholar
Digital Library
- Neel Varshney. Lightning network has 1 percent success rate with transactions larger than $200, controversial research says. Hard Fork, June 2018.Google Scholar
- Shira Werman and Aviv Zohar. Avoiding deadlocks in payment channel networks. In Data Privacy Management, Cryptocurrencies and Blockchain Technology, pages 175--187. Springer, 2018.Google Scholar
- Haifeng Yu, Ivica Nikolic, Ruomu Hou, and Prateek Saxena. Ohie: Blockchain scaling made simple. arXiv preprint arXiv:1811.12628, 2018.Google Scholar
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