arXiv subjects

Bruno França

Publications and source records attributed to Bruno França.

5 recordsLinked to original sources

arXiv2025

ChonkyBFT: Consensus Protocol of ZKsync

We present ChonkyBFT, a partially-synchronous Byzantine fault-tolerant (BFT) consensus protocol used in the ZKsync system. The proposed protocol is a hybrid protocol inspired by FAB Paxos, Fast-HotStuff, and HotStuff-2. It is a committee-based protocol with only one round of voting, single slot finality, quadratic communication, and n >= 5f + 1 fault tolerance. This design enables its effective application within the context of the ZKsync rollup, achieving its most critical goals: simplicity, low transaction latency, and reduced system complexity. The target audience for this paper is the ZKsync community and others worldwide who seek assurance in the safety and security of the ZKsync protocols. The described consensus protocol has been implemented, analyzed, and tested using formal methods.

cs.DC↗

arXiv2024

Albatross: An optimistic consensus algorithm

The consensus protocol is a critical component of distributed ledgers and blockchains. Achieving consensus over a decentralized network poses challenges to transaction finality and performance. Currently, the highest-performing consensus algorithms are speculative BFT algorithms, which, however, compromise on the transaction finality guarantees offered by their non-speculative counterparts. In this paper, we introduce Albatross, a Proof-of-Stake (PoS) blockchain consensus algorithm that aims to combine the best of both worlds. At its heart, Albatross is a high-performing, speculative BFT algorithm that offers strong probabilistic finality. We complement this by periodically guaranteeing finality through the Tendermint protocol. We prove our protocol to be secure under standard BFT assumptions and analyze its performance both on a theoretical and practical level. For that, we provide an open-source Rust implementation of Albatross. Our real-world measurements support that our protocol has a performance close to the theoretical maximum for single-chain Proof-of-Stake consensus algorithms.

cs.CR↗

arXiv2019

Deep Ocean: A blockchain-agnostic dark pool protocol

We introduce a new cryptographic protocol, called Deep Ocean, that implements a blockchain-agnostic dark pool for cryptocurrencies. Deep Ocean is a layer-two protocol, meaning that it can work with any two cryptocurrencies, as long as there exists an underlying settlement mechanism, for example performing atomic swaps.

cs.CR↗

arXiv2019

Enso: A general-purpose virtual machine

In this paper we introduce Enso, a virtual machine designed to be used as general-purpose state transition function in blockchains. This design allows the blockchain application logic to be coded into the state, instead of into the state transition function, making it much more flexible and easier to modify. A byproduct is reducing the frequency of forks, concerted or not.

cs.CR↗

arXiv2019

Katal: A standard framework for finance

Katal is a new blockchain that provides a standard way to build and deploy decentralized financial applications. It brings together all the components necessary for the backend of a financial application, namely: a high-performance consensus, an authenticated data feed system, a standard for financial contracts and connectivity to the rest of the blockchain ecosystem. Katal enables and simplifies the creation of financial services that are non-custodial, trustless, fast, convenient and interoperable.

cs.CR↗