We continue to explore the marvelous world of consensus in the Asynchronous model. In this post, we present Ben-Or’s classic protocol from 1983. In the next post, we will present a more modern version that is a simplified version from our paper. In the previous post we defined the problem...| decentralizedthoughts.github.io
Reliable Broadcast is an important building block of many Asynchronous protocols. There is a broadcaster that has some input value, $v$, and a non-faulty party that terminates needs to output a value. Reliable Broadcast is defined via two properties: Validity: If the broadcaster is non-faulty then eventually all non-faulty parties...| decentralizedthoughts.github.io
Advanced cryptography: Symbolic methods for security| cseweb.ucsd.edu
In this third post, we conclude with the celebrated Fischer, Lynch, and Paterson impossibility result from 1985. It is the fundamental lower bound for consensus in the asynchronous model. Theorem 1 (FLP85): Any protocol $\mathcal{P}$ solving consensus in the asynchronous model that is resilient to even just one crash failure...| decentralizedthoughts.github.io
A very useful tool in Asynchronus distributed computing is Reliable Broadcast, or simply called Broadcast. It allows a leader to send a message, knowing that all parties will eventually receive the same message, even if a malicious adversary control $f$ parties and $f<n/3$. Broadcast is deterministic and takes just a...| decentralizedthoughts.github.io
In this series of posts, we explore what can be done in the Asynchronous model. This model seems challenging because the adversary can delay messages by any bounded time. By the end of this series, you will see that almost everything that can be done in synchrony can be obtained...| decentralizedthoughts.github.io
In this series of posts, we explore the marvelous world of consensus in the Asynchronous model. In this third post, we present a modern version of Ben-Or’s classic protocol that is part of our new work on Asynchronous Agreement. In the first post we defined the problem and in the...| decentralizedthoughts.github.io
After we fix the communication model, synchrony, asynchrony, or partial synchrony, and a threshold adversary we still have 5 important modeling decisions about the adversary power: The type of corruption (passive, crash, omission, or Byzantine). The computational power of the adversary (unbounded, computational, or fine-grained). The adaptivity of the adversary...| decentralizedthoughts.github.io
In the standard distributed computing model, the communication uncertainty is captured by an adversary that can control the message delays. The communication model defines the limits to the power of the adversary to delay messages. There are three basic communication models: the Synchronous model, the Asynchronous model, and the Partial...| decentralizedthoughts.github.io