Dynastie des Comnènes

As easy as ABC: Optimal (A)ccountable (B)yzantine (C)onsensus is easy!

Rachid Guerraoui, Vincent Gramoli, Seth Gilbert, Jovan Komatovic, Pierre Philippe Civit

It is known that the agreement property of the Byzantine consensus problem among n processes can be violated in a non-synchronous system if the number of faulty processes exceeds t0 = ┌n/3┐ − 1 [10], [19]. In this paper, we investigate the accountable Byza ...

IEEE2022

Byzantine Consensus is Θ(n^2): The Dolev-Reischuk Bound is Tight even in Partial Synchrony!

Rachid Guerraoui, Vincent Gramoli, Seth Gilbert, Jovan Komatovic, Manuel José Ribeiro Vidigueira, Pierre Philippe Civit

The Dolev-Reischuk bound says that any deterministic Byzantine consensus protocol has (at least) quadratic communication complexity in the worst case. While it has been shown that the bound is tight in synchronous environments, it is still unknown whether ...

Dagstuhl Publishing2022

AGGREGATHOR: Byzantine Machine Learning via Robust Gradient Aggregation

Rachid Guerraoui, El Mahdi El Mhamdi, Sébastien Louis Alexandre Rouault, Arsany Hany Abdelmessih Guirguis, Georgios Damaskinos

We present AGGREGATHOR, a framework that implements state-of-the-art robust (Byzantine-resilient) distributed stochastic gradient descent. Following the standard parameter server model, we assume that a minority of worker machines can be controlled by an a ...

2019

Timing Analysis of Leader-Based and Decentralized Byzantine Consensus Algorithms

André Schiper, Martin Hutle, Fatemeh Borran

We compare in an analytical way two leader-based and decentralized algorithms (that is, algorithms that do not use a leader) for Byzantine consensus with strong validity. We show that for \emph{the algorithms we analyzed}, in most cases, the decentralized ...

IEEE2011

On the Reduction of Atomic Broadcast to Consensus with Byzantine Faults

André Schiper, Martin Hutle, Zarko Milosevic

We investigate the reduction of atomic broadcast to consensus in systems with Byzantine faults. Among the several definitions of Byzantine consensus that differ only by their validity property, we identify those equivalent to atomic broadcast. Finally, we ...

Ieee Computer Soc Press, Customer Service Center, Po Box 3014, 10662 Los Vaqueros Circle, Los Alamitos, Ca 90720-1264 Usa2011