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
This post explains in simple words a recent development in the theory and practice of directed acyclic graph-based (DAG-based) Byzantine Fault Tolerance (BFT) consensus, published in three prestigious peer-reviewed conferences, and currently being implemented by several Blockchain companies, e.g., Aptos, Celo, Mysten Labs, and Somelier. DAG-Rider: All You Need Is...| 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
We explore a family of broadcast protocols in the authenticated setting in which a designated sender wants to create a delivery-certificate of its input value. After describing the base protocol we call Provable Broadcast ($PB$), we explore the surprising power of simply running $PB$ two times in a row, then...| decentralizedthoughts.github.io
Verifiable Information Dispersal (or VID) has its roots in the work of Michael Rabin, 1989 which introduced the notion of Information Dispersal (ID). Adding verifiability (referred to as binding in this post) to obtain VIDs was done by Garay, Gennaro, Jutla, and Rabin, 1998 (called SSRI). Cachin and Tessaro, 2004...| decentralizedthoughts.github.io
TL;DR: Shoal++ is a novel DAG-BFT system that supercharges Shoal to achieve near-optimal theoretical latency while preserving the high throughput and robustness of state-of-the-art certified DAG BFT protocols. We evaluated Shoal++ against state-of-the-art DAG BFT protocols, such as Bullshark and Shoal — as well as a concurrent DAG effort, Mysticeti...| decentralizedthoughts.github.io
In this blog post, we will explain the core ideas behind Sailfish, a latency-efficient DAG-based protocol. In essence, Sailfish is a reliable-broadcast (RBC) based DAG protocol that supports leaders in every RBC round. It commits leader vertices within 1RBC + $\delta$ time and non-leader vertices within 2RBC + $\delta$ time,...| decentralizedthoughts.github.io
A few years ago if you asked “Can blockchains scale?” most people would give three reasons why, fundamentally, the answer is “No!” Data: every transaction needs to be replicated by every miner (validator). So increasing security by adding more validators inherently causes more replication. Having $n$ validators implies that your...| decentralizedthoughts.github.io
