Byzantine AgreementByzantine Agreement • November 15th, 2017
In order to make flying safer, researchers studied possible failures of various sensors and machines used in airplanes. While trying to model the failures, they were confronted with the following problem: Failing machines did not just crash, instead they sometimes showed arbitrary behavior before stopping com- pletely. With these insights researchers modeled failures as arbitrary failures, not restricted to any patterns.
ContractByzantine Agreement • November 18th, 2024
AbstractByzantine Agreement • July 25th, 2021
Claim 4.12. Consider an execution of π with A3 where all parties starts with input bit 0. Then, conditioned on the event 𝖲 , all honest parties output 1 with noticeable probability.
Round-Optimal Byzantine AgreementByzantine Agreement • March 1st, 2022
Concurrent Asynchronous Byzantine Agreement in Expected-Constant Rounds, Revisited∗Byzantine Agreement • December 25th, 2023
17These probabilities only need to be computable by the simulator to give a constructive description of . Note that an existential argument, which is sufficient to complete the emulation, would not require to calculate those probabilities at all. Nonetheless, we opt for a constructive approach to better illustrate the concept.
Efficient Byzantine Agreement with Faulty MinoritysByzantine Agreement • December 12th, 2007
Abstract. Byzantine Agreement (BA) among n players allows the play- ers to agree on a value, even when up to t of the players are faulty.
Combining Asynchronous and Synchronous Byzantine Agreement:Byzantine Agreement • December 26th, 2023
For the remainder of the following sections, let us call a message (i, v, L) correctly formed, if it L contains at least 3n valid signatures on v from distinct parties.
Efficient Agreement Over Byzantine GossipByzantine Agreement • January 13th, 2024
Byzantine agreement (BA) asks for a set of parties to reach agreement in an adversarial setting. A central question is how to construct efficient BA protocols that scale well with the number of parties. In particular, the communication complexity is a critical barrier for large-scale implementations.
Byzantine Agreement with HomonymsByzantine Agreement • November 4th, 2020
Proposition 28 (Unforgeability) If α correct processes with identifier i perform Broadcast(i, m, r) in superround r and some correct process performs Accept(i, α′, m, r) in superround r then r ≤ r and 0 ≤ α ≤ α + fi.
Grouping Byzantine AgreementByzantine Agreement • November 29th, 2004
Byzantine Agreement Byzantine AgreementByzantine Agreement • December 19th, 2022
The Byzantine Agreement – part 2Byzantine Agreement • October 18th, 2017
• If the processes start with different initial values, then the final decision could be any of these (as long as it is consistent)
Detectable Byzantine Agreement Secure Against Faulty MajoritiesByzantine Agreement • September 17th, 2020
corrupted players. An adversary who can make the protocol fail with probability ε can be used to forge a signature with probability ε/n.
Not a COINcidence: Sub-Quadratic Asynchronous Byzantine Agreement WHPByzantine Agreement • August 4th, 2020
King and Saia were the first to break the quadratic word complexity bound for Byzantine Agreement in synchronous systems against an adaptive adversary, and Algorand broke this bound with near- optimal resilience (first in the synchronous model and then with eventual-synchrony). Yet the question of asynchronous sub-quadratic Byzantine Agreement remained open. To the best of our knowledge, we are the first to answer this question in the affirmative. A key component of our solution is a shared coin algorithm based on a VRF. A second essential ingredient is VRF-based committee sampling, which we formalize and utilize in the asynchronous model for the first time. Our algorithms work against a delayed-adaptive adversary, which cannot perform after-the-fact removals but has full control of Byzantine processes and full information about communication in earlier rounds. Using committee sampling and our shared coin, we solve Byzantine Agreement with high probability, with a word complexity of O(
Validity in Network-Agnostic Byzantine AgreementByzantine Agreement • October 28th, 2024
In Byzantine Agreement (BA), there is a set of n parties, from which up to t can act byzantine. All honest parties must eventually decide on a common value (agreement), which must belong to a set determined by the inputs (validity). Depending on the use case, this set can grow or shrink, leading to various possible desiderata collectively known as validity conditions. Varying the validity property requirement can affect the regime under which BA is solvable. We study how the selected validity property impacts BA solvability in the network-agnostic model, where the network can either be synchronous with up to ts byzantine parties or asynchronous with up to ta ts byzantine parties.
Accurate Byzantine Agreement with FeedbackByzantine Agreement • May 26th, 2011
Jerusalem, IsraelByzantine Agreement • November 19th, 2007
This constitutes significant progress over the best known randomized BA protocol in the same setting which has a round-complexity of Θ( t ) rounds [9], and answers an open problem
Asynchronous Byzantine Agreement with Subquadratic CommunicationByzantine Agreement • June 12th, 2023
Byzantine Agreement with Optimal Early Stopping, Optimal Resilience and Polynomial ComplexityByzantine Agreement • April 22nd, 2015
We provide the first protocol that solves Byzantine agree- ment with optimal early stopping (min f + 2, t + 1 rounds) and optimal resilience (n > 3t) using polynomial message size and computation.
On Byzantine Agreement over (2, 3)-Uniform HypergraphsByzantine Agreement • December 15th, 2004
Visiting Byzantine Agreement underlying Ad Hoc EnvironmentByzantine Agreement • September 21st, 2010
The Mobile Ad Hoc Network (MANET) has become more popular because the MANET is a self-organizing, self-configuring, and an instantly deployable multi-hop wireless network that responds to application needs without any fixed infrastructure. Moreover, the MANET is fault-tolerant and reliable. A mechanism is needed in the MANET that allows a set of nodes to agree on a common value. The distributed Byzantine Agreement (BA) problem is one of the most important issues in designing a fault-tolerant system. In many cases, reaching a common agreement among fault-free nodes in coping with the influence from faulty components is crucial in a fault-tolerant system. When a common agreement is achieved, all fault-free nodes in the system can produce stable results without any influence from the faulty components. In this study, the BA problem is visited in a MANET, in which the components are subject to a malicious fault. The proposed protocol can tolerate the maximum number of allowable faulty node
Optimal Agreement in a Generalized Scale-Free NetworkByzantine Agreement • September 5th, 2008
Generally, the task in a distributed system must achieve an agreement. It requires a set of processors to agree on a common value even if some components are corrupted. There are significant studies on this agreement problem in a regularized network environment, such as the fully connected, broadcast, and multicast networks. Recently, many large complex networks have emerged and displayed a scale-free feature, which influences the system to reach a common value differently. Such a unanimity problem is called the Byzantine Agreement (BA). The BA problem is one of the most important problems in designing a fault-tolerant distributed system. Unfortunately, existing BA protocols and results cannot cope with the new network environment and the BA problem thus needs to be revisited. In this paper, a new BA protocol is proposed to adapt to the scale-free network environment and derive its bound of allowable faulty components with the minimum number of message exchanges. We have proved the cor
Byzantine AgreementByzantine Agreement • June 25th, 2007
At the next round all players measure all the pieces they have; a leader is selected according to the shared minimum; and the corresponding measured bit serves as the “global coin”.
Round Efficient Byzantine Agreement from VDFsByzantine Agreement • June 27th, 2022
CS6410 – ByzantineByzantine Agreement • October 22nd, 2016
Fully-Distributed Byzantine Agreement in Sparse NetworksByzantine Agreement • October 18th, 2024
Byzantine agreement is a fundamental problem in fault-tolerant distributed networks that has been stud- ied intensively for the last four decades. Most of these works designed protocols for complete networks. A key goal in Byzantine protocols is to tolerate as many Byzantine nodes as possible — up to O(n) Byzantine nodes (n is the total network size).
The Byzantine Agreement – part 2Byzantine Agreement • October 18th, 2017
ContractByzantine Agreement • May 24th, 2022
Early Stopping Byzantine Agreement inByzantine Agreement • May 26th, 2024
Abstract. In this paper, we present two early stopping Byzantine agree- ment protocols in the authenticated setting against a corrupt minority t < n/2, where t represents the maximum number of malicious parties. Early stopping protocols ensure termination within a number of rounds determined solely by the actual number of malicious nodes f present during execution, irrespective of t.
PKC’2021Byzantine Agreement • November 17th, 2020
Reaching Agreement on an Unknown Network with Partial Graphic InformationByzantine Agreement • December 10th, 2004
The Byzantine Agreement (BA) is an important topic in the reliable distributed system because the system can cope with the influences from faulty components when the agreement is achieved. In the literature concerned, the BA problem has been well formulated in a Fully Connected Network (FCN) and a Generalized Connected Network (GCN) under the assumption that each processor in the network has the common knowledge of the graphic information about the entire network structure. However, in the real world, each processor may not have the common knowledge of the graphic information about the entire network structure. That is, the processors may only have the partial knowledge as to their own graphic information. In this paper, the Byzantine Agreement problem will be visited in an Unknown Network (UNet) to increase the capability of fault tolerance by allowing faulty processors with dual failure mode. The proposed protocols, the Unknown Agreement Protocol (UAP) and the Relay Channel (RC), use
Byzantine Agreement in Polynomial Time with Near-Optimal Resilience∗Byzantine Agreement • February 28th, 2022
Byzantine AgreementByzantine Agreement • May 28th, 2022
Asynchronous Byzantine Agreement in Incomplete NetworksByzantine Agreement • May 27th, 2020
The Byzantine agreement problem is considered to be a core prob- lem in distributed systems. For example, Byzantine agreement is needed to build a blockchain, a totally ordered log of records. Blockchains are asynchronous distributed systems, fault-tolerant against Byzantine nodes.
Faster Agreement Via a Spectral Method for Detecting Malicious BehaviorByzantine Agreement • September 28th, 2021
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