6 Search Results for "Goren, Guy"


Document
Security Analysis of Filecoin’s Expected Consensus in the Byzantine vs Honest Model

Authors: Xuechao Wang, Sarah Azouvi, and Marko Vukolić

Published in: LIPIcs, Volume 282, 5th Conference on Advances in Financial Technologies (AFT 2023)


Abstract
Filecoin is the largest storage-based open-source blockchain, both by storage capacity (>11EiB) and market capitalization. This paper provides the first formal security analysis of Filecoin’s consensus (ordering) protocol, Expected Consensus (EC). Specifically, we show that EC is secure against an arbitrary adversary that controls a fraction β of the total storage for β m < 1- e^{-(1-β)m}, where m is a parameter that corresponds to the expected number of blocks per round, currently m = 5 in Filecoin. We then present an attack, the n-split attack, where an adversary splits the honest miners between multiple chains, and show that it is successful for β m ≥ 1- e^{-(1-β)m}, thus proving that β m = 1- e^{-(1-β)m} is the tight security threshold of EC. This corresponds roughly to an adversary with 20% of the total storage pledged to the chain. Finally, we propose two improvements to EC security that would increase this threshold. One of these two fixes is being implemented as a Filecoin Improvement Proposal (FIP).

Cite as

Xuechao Wang, Sarah Azouvi, and Marko Vukolić. Security Analysis of Filecoin’s Expected Consensus in the Byzantine vs Honest Model. In 5th Conference on Advances in Financial Technologies (AFT 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 282, pp. 5:1-5:21, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)


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@InProceedings{wang_et_al:LIPIcs.AFT.2023.5,
  author =	{Wang, Xuechao and Azouvi, Sarah and Vukoli\'{c}, Marko},
  title =	{{Security Analysis of Filecoin’s Expected Consensus in the Byzantine vs Honest Model}},
  booktitle =	{5th Conference on Advances in Financial Technologies (AFT 2023)},
  pages =	{5:1--5:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-303-4},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{282},
  editor =	{Bonneau, Joseph and Weinberg, S. Matthew},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2023.5},
  URN =		{urn:nbn:de:0030-drops-191943},
  doi =		{10.4230/LIPIcs.AFT.2023.5},
  annote =	{Keywords: Decentralized storage, Consensus, Security analysis}
}
Document
Base Fee Manipulation in Ethereum’s EIP-1559 Transaction Fee Mechanism

Authors: Sarah Azouvi, Guy Goren, Lioba Heimbach, and Alexander Hicks

Published in: LIPIcs, Volume 281, 37th International Symposium on Distributed Computing (DISC 2023)


Abstract
In 2021 Ethereum adjusted the transaction pricing mechanism by implementing EIP-1559, which introduces the base fee - a network fee that is burned and dynamically adjusts to the network demand. The authors of the Ethereum Improvement Proposal (EIP) noted that a miner with more than 50% of the mining power could be incentivized to deviate from the honest mining strategy. Instead, such a miner could propose a series of empty blocks to artificially lower demand and increase her future rewards. In this paper, we generalize this attack and show that under rational player behavior, deviating from the honest strategy can be profitable for a miner with less than 50% of the mining power. We show that even when miners do not collaborate, it is at times rational for smaller miners to join the attack. Finally, we propose a mitigation to address the identified vulnerability.

Cite as

Sarah Azouvi, Guy Goren, Lioba Heimbach, and Alexander Hicks. Base Fee Manipulation in Ethereum’s EIP-1559 Transaction Fee Mechanism. In 37th International Symposium on Distributed Computing (DISC 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 281, pp. 6:1-6:22, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)


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@InProceedings{azouvi_et_al:LIPIcs.DISC.2023.6,
  author =	{Azouvi, Sarah and Goren, Guy and Heimbach, Lioba and Hicks, Alexander},
  title =	{{Base Fee Manipulation in Ethereum’s EIP-1559 Transaction Fee Mechanism}},
  booktitle =	{37th International Symposium on Distributed Computing (DISC 2023)},
  pages =	{6:1--6:22},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-301-0},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{281},
  editor =	{Oshman, Rotem},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2023.6},
  URN =		{urn:nbn:de:0030-drops-191325},
  doi =		{10.4230/LIPIcs.DISC.2023.6},
  annote =	{Keywords: blockchain, Ethereum, transaction fee mechanism, EIP-1559}
}
Document
Null Messages, Information and Coordination

Authors: Raïssa Nataf, Guy Goren, and Yoram Moses

Published in: LIPIcs, Volume 281, 37th International Symposium on Distributed Computing (DISC 2023)


Abstract
This paper investigates the role that null messages play in synchronous systems with and without failures, and provides necessary and sufficient conditions on the structure of protocols for information transfer and coordination there. We start by introducing a new and more refined definition of null messages. A generalization of message chains that allow these null messages is provided, and is shown to be necessary and sufficient for information transfer in reliable systems. Coping with crash failures requires a much richer structure, since not receiving a message may be the result of the sender’s failure. We introduce a class of communication patterns called resilient message blocks, which impose a stricter condition on protocols than the silent choirs of Goren and Moses (2020). Such blocks are shown to be necessary for information transfer in crash-prone systems. Moreover, they are sufficient in several cases of interest, in which silent choirs are not. Finally, a particular combination of resilient message blocks is shown to be necessary and sufficient for solving the Ordered Response coordination problem.

Cite as

Raïssa Nataf, Guy Goren, and Yoram Moses. Null Messages, Information and Coordination. In 37th International Symposium on Distributed Computing (DISC 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 281, pp. 30:1-30:21, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)


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@InProceedings{nataf_et_al:LIPIcs.DISC.2023.30,
  author =	{Nataf, Ra\"{i}ssa and Goren, Guy and Moses, Yoram},
  title =	{{Null Messages, Information and Coordination}},
  booktitle =	{37th International Symposium on Distributed Computing (DISC 2023)},
  pages =	{30:1--30:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-301-0},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{281},
  editor =	{Oshman, Rotem},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2023.30},
  URN =		{urn:nbn:de:0030-drops-191564},
  doi =		{10.4230/LIPIcs.DISC.2023.30},
  annote =	{Keywords: null messages, fault tolerance, coordination, information flow, knowledge analysis}
}
Document
Brief Announcement
Brief Announcement: Null Messages, Information and Coordination

Authors: Raïssa Nataf, Guy Goren, and Yoram Moses

Published in: LIPIcs, Volume 246, 36th International Symposium on Distributed Computing (DISC 2022)


Abstract
This paper investigates how null messages can transfer information in fault-prone synchronous systems. The notion of an f-resilient message block is defined and is shown to capture the fundamental communication pattern for knowledge transfer. In general, this pattern combines both null messages and explicit messages. It thus provides a fault-tolerant extension of the classic notion of a message-chain. Based on the above, we provide tight necessary and sufficient characterizations of the generalized communication patterns that can serve to solve the distributed tasks of (nice-run) Signalling and Ordered Response.

Cite as

Raïssa Nataf, Guy Goren, and Yoram Moses. Brief Announcement: Null Messages, Information and Coordination. In 36th International Symposium on Distributed Computing (DISC 2022). Leibniz International Proceedings in Informatics (LIPIcs), Volume 246, pp. 49:1-49:3, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)


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@InProceedings{nataf_et_al:LIPIcs.DISC.2022.49,
  author =	{Nataf, Ra\"{i}ssa and Goren, Guy and Moses, Yoram},
  title =	{{Brief Announcement: Null Messages, Information and Coordination}},
  booktitle =	{36th International Symposium on Distributed Computing (DISC 2022)},
  pages =	{49:1--49:3},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-255-6},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{246},
  editor =	{Scheideler, Christian},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2022.49},
  URN =		{urn:nbn:de:0030-drops-172409},
  doi =		{10.4230/LIPIcs.DISC.2022.49},
  annote =	{Keywords: null messages, fault tolerance, coordination, information flow}
}
Document
Brief Announcement
Brief Announcement: Probabilistic Indistinguishability and The Quality of Validity in Byzantine Agreement

Authors: Guy Goren, Yoram Moses, and Alexander Spiegelman

Published in: LIPIcs, Volume 209, 35th International Symposium on Distributed Computing (DISC 2021)


Abstract
Lower bounds and impossibility results in distributed computing are both intellectually challenging and practically important. Hundreds if not thousands of proofs appear in the literature, but surprisingly, the vast majority of them apply to deterministic algorithms only. Probabilistic protocols have been around for at least four decades and are receiving a lot of attention with the emergence of blockchain systems. Nonetheless, we are aware of only a handful of randomized lower bounds. In this work we provide a formal framework for reasoning about randomized distributed algorithms. We generalize the notion of indistinguishability, the most useful tool in deterministic lower bounds, to apply to a probabilistic setting. We apply this framework to prove a result of independent interest. Namely, we completely characterize the quality of decisions that protocols for a randomized multi-valued Consensus problem can guarantee in an asynchronous environment with Byzantine faults. We use the new notion to prove a lower bound on the guaranteed probability that honest parties will not decide on a possibly bogus value proposed by a malicious party. Finally, we show that the bound is tight by providing a protocol that matches it. This brief announcement consists of an introduction to the full paper [Guy Goren et al., 2020] by the same title. The interested reader is advised to consult the full paper for a detailed exposition.

Cite as

Guy Goren, Yoram Moses, and Alexander Spiegelman. Brief Announcement: Probabilistic Indistinguishability and The Quality of Validity in Byzantine Agreement. In 35th International Symposium on Distributed Computing (DISC 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 209, pp. 57:1-57:4, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)


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@InProceedings{goren_et_al:LIPIcs.DISC.2021.57,
  author =	{Goren, Guy and Moses, Yoram and Spiegelman, Alexander},
  title =	{{Brief Announcement: Probabilistic Indistinguishability and The Quality of Validity in Byzantine Agreement}},
  booktitle =	{35th International Symposium on Distributed Computing (DISC 2021)},
  pages =	{57:1--57:4},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-210-5},
  ISSN =	{1868-8969},
  year =	{2021},
  volume =	{209},
  editor =	{Gilbert, Seth},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2021.57},
  URN =		{urn:nbn:de:0030-drops-148596},
  doi =		{10.4230/LIPIcs.DISC.2021.57},
  annote =	{Keywords: Indistinguishability, probabilistic lower bounds, Byzantine agreement}
}
Document
Distributed Dispatching in the Parallel Server Model

Authors: Guy Goren, Shay Vargaftik, and Yoram Moses

Published in: LIPIcs, Volume 179, 34th International Symposium on Distributed Computing (DISC 2020)


Abstract
With the rapid increase in the size and volume of cloud services and data centers, architectures with multiple job dispatchers are quickly becoming the norm. Load balancing is a key element of such systems. Nevertheless, current solutions to load balancing in such systems admit a paradoxical behavior in which more accurate information regarding server queue lengths degrades performance due to herding and detrimental incast effects. Indeed, both in theory and in practice, there is a common doubt regarding the value of information in the context of multi-dispatcher load balancing. As a result, both researchers and system designers resort to more straightforward solutions, such as the power-of-two-choices to avoid worst-case scenarios, potentially sacrificing overall resource utilization and system performance. A principal focus of our investigation concerns the value of information about queue lengths in the multi-dispatcher setting. We argue that, at its core, load balancing with multiple dispatchers is a distributed computing task. In that light, we propose a new job dispatching approach, called Tidal Water Filling, which addresses the distributed nature of the system. Specifically, by incorporating the existence of other dispatchers into the decision-making process, our protocols outperform previous solutions in many scenarios. In particular, when the dispatchers have complete and accurate information regarding the server queue lengths, our policies significantly outperform all existing solutions.

Cite as

Guy Goren, Shay Vargaftik, and Yoram Moses. Distributed Dispatching in the Parallel Server Model. In 34th International Symposium on Distributed Computing (DISC 2020). Leibniz International Proceedings in Informatics (LIPIcs), Volume 179, pp. 14:1-14:18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


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@InProceedings{goren_et_al:LIPIcs.DISC.2020.14,
  author =	{Goren, Guy and Vargaftik, Shay and Moses, Yoram},
  title =	{{Distributed Dispatching in the Parallel Server Model}},
  booktitle =	{34th International Symposium on Distributed Computing (DISC 2020)},
  pages =	{14:1--14:18},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-168-9},
  ISSN =	{1868-8969},
  year =	{2020},
  volume =	{179},
  editor =	{Attiya, Hagit},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2020.14},
  URN =		{urn:nbn:de:0030-drops-130929},
  doi =		{10.4230/LIPIcs.DISC.2020.14},
  annote =	{Keywords: Distributed load balancing, Join the Shortest Queue, Tidal Water Filling,  Parallel Server Model}
}
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