Sprites and State Channels: Payment Networks that Go Faster Than Lightning

Miller, Andrew; Bentov, Iddo; Bakshi, Surya; Kumaresan, Ranjit; McCorry, Patrick

doi:10.1007/978-3-030-32101-7_30

Cited by 188 publications

(173 citation statements)

References 28 publications

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“…Miller et al [53] propose a construction for payment channels to reduce the time that funds are locked at intermediate payment channels (i.e., collateral cost), an interesting problem but orthogonal to our work. Moreover, they formalize their con-struction for multi-hop payments as an ideal functionality.…”

Section: Related Workmentioning

confidence: 99%

Concurrency and Privacy with Payment-Channel Networks

Malavolta

Moreno-Sanchez

Kate

et al. 2017

Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security

214

161

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Permissionless blockchains protocols such as Bitcoin are inherently limited in transaction throughput and latency. Current efforts to address this key issue focus on off-chain payment channels that can be combined in a Payment-Channel Network (PCN) to enable an unlimited number of payments without requiring to access the blockchain other than to register the initial and final capacity of each channel. While this approach paves the way for low latency and high throughput of payments, its deployment in practice raises several privacy concerns as well as technical challenges related to the inherently concurrent nature of payments that have not been sufficiently studied so far.In this work, we lay the foundations for privacy and concurrency in PCNs, presenting a formal definition in the Universal Composability framework as well as practical and provably secure solutions. In particular, we present Fulgor and Rayo. Fulgor is the first payment protocol for PCNs that provides provable privacy guarantees for PCNs and is fully compatible with the Bitcoin scripting system. However, Fulgor is a blocking protocol and therefore prone to deadlocks of concurrent payments as in currently available PCNs. Instead, Rayo is the first protocol for PCNs that enforces non-blocking progress (i.e., at least one of the concurrent payments terminates). We show through a new impossibility result that non-blocking progress necessarily comes at the cost of weaker privacy. At the core of Fulgor and Rayo is Multi-Hop HTLC, a new smart contract, compatible with the Bitcoin scripting system, that provides conditional payments while reducing running time and communication overhead with respect to previous approaches. Our performance evaluation of Fulgor and Rayo shows that a payment with 10 intermediate users takes as few as 5 seconds, thereby demonstrating their feasibility to be deployed in practice.

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Section: Related Workmentioning

confidence: 99%

Concurrency and Privacy with Payment-Channel Networks

Malavolta

Moreno-Sanchez

Kate

et al. 2017

Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security

214

161

View full text Add to dashboard Cite

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“…While there are different payment channel designs [2,3,4,5,6], the Bitcoin Lightning Network [7] is arguably the most prevalent PCN implementation to date: at the time of writing, it features a large, rapidly growing network of around 2,500 public nodes and a total capacity of more than 400 BTC (≈ 1.4 million USD). At the same time, this makes the Lightning Network an attractive attack surface for adversaries.…”

Section: Introductionmentioning

confidence: 99%

“…Bitcoind, https://github.com/bitcoin/bitcoin, Accessed: 2018-10-242 Lnd, https://github.com/lightningnetwork/lnd, Accessed: 2018-10-24 3 https://gitlab.tu-berlin.de/rohrer/discharged-pc-data…”

mentioning

confidence: 99%

Discharged Payment Channels: Quantifying the Lightning Network's Resilience to Topology-Based Attacks

Rohrer

Malliaris

Tschorsch

2019

2019 IEEE European Symposium on Security and Privacy Workshops (EuroS&PW)

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The Lightning Network is the most widely used payment channel network (PCN) to date, making it an attractive attack surface for adversaries. In this paper, we analyze the Lightning Network's PCN topology and investigate its resilience towards random failures and targeted attacks. In particular, we introduce the notions of channel exhaustion and node isolation attacks and show that the Lightning Network is susceptible to these attacks. In a preliminary analysis, we confirm that the Lightning Network can be classified as a small-world and scalefree network. Based on these findings, we develop a series of strategies for targeted attacks and introduce metrics that allow us to quantify the adversary's advantage. Our results indicate that an attacker who is able to remove a certain number of nodes should follow a centrality-based strategy, while a resource-limited attacker who aims for high efficiency should employ a highest ranked minimum cut strategy.• We study the current state of the Lightning Network's PCN topology and assess its resilience to random failures and targeted attacks. • We systematize topology-based attacks against PCNs. • We introduce channel exhaustion and node isolation attacks as additional attack vectors. • We develop various adversarial strategies and quantify their prospects in terms of the adversarial success.

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“…The blockchain is used only for disputes and settlements. Examples of off-chain solutions include payment channels [31] and state channels [39].…”

Section: Related Workmentioning

confidence: 99%

Towards Scaling Blockchain Systems via Sharding

Dang

Dinh

Loghin

et al. 2019

Proceedings of the 2019 International Conference on Management of Data

388

159

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Existing blockchain systems scale poorly because of their distributed consensus protocols. Current attempts at improving blockchain scalability are limited to cryptocurrency. Scaling blockchain systems under general workloads (i.e., noncryptocurrency applications) remains an open question.In this work, we take a principled approach to apply sharding, which is a well-studied and proven technique to scale out databases, to blockchain systems in order to improve their transaction throughput at scale. This is challenging, however, due to the fundamental difference in failure models between databases and blockchain. To achieve our goal, we first enhance the performance of Byzantine consensus protocols, by doing so we improve individual shards' throughput. Next, we design an efficient shard formation protocol that leverages a trusted random beacon to securely assign nodes into shards. We rely on trusted hardware, namely Intel SGX, to achieve high performance for both consensus and shard formation protocol. Third, we design a general distributed transaction protocol that ensures safety and liveness even when transaction coordinators are malicious. Finally, we conduct an extensive evaluation of our design both on a local cluster and on Google Cloud Platform. The results show that our consensus and shard formation protocols outperform state-of-the-art solutions at scale. More importantly, our sharded blockchain reaches a high throughput that can handle Visa-level workloads, and is the largest ever reported in a realistic environment.

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Sprites and State Channels: Payment Networks that Go Faster Than Lightning

Cited by 188 publications

References 28 publications

Concurrency and Privacy with Payment-Channel Networks

Concurrency and Privacy with Payment-Channel Networks

Discharged Payment Channels: Quantifying the Lightning Network's Resilience to Topology-Based Attacks

Towards Scaling Blockchain Systems via Sharding

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