5 research outputs found
Practical Settlement Bounds for Longest-Chain Consensus
Nakamoto\u27s longest-chain consensus paradigm now powers the bulk of the world\u27s cryptocurrencies and distributed finance infrastructure. An emblematic property of longest-chain consensus is that it provides probabilistic settlement guarantees that strengthen over time. This makes the exact relationship between settlement error and settlement latency a critical aspect of the protocol that both users and system designers must understand to make informed decisions. A recent line of work has finally provided a satisfactory rigorous accounting of this relationship for proof-of-work longest-chain protocols, but those techniques do not appear to carry over to the proof-of-stake setting.
This article develops explicit, rigorous settlement bounds for proof-of-stake longest-chain protocols, placing them on equal footing with their proof-of-work counterparts. Our techniques apply with some adaptations also to the proof-of-work setting where they provide improvements to the state-of-the-art settlement bounds for proof-of-work protocols
SoK: Diving into DAG-based Blockchain Systems
Blockchain plays an important role in cryptocurrency markets and technology
services. However, limitations on high latency and low scalability retard their
adoptions and applications in classic designs. Reconstructed blockchain systems
have been proposed to avoid the consumption of competitive transactions caused
by linear sequenced blocks. These systems, instead, structure
transactions/blocks in the form of Directed Acyclic Graph (DAG) and
consequently re-build upper layer components including consensus, incentives,
\textit{etc.} The promise of DAG-based blockchain systems is to enable fast
confirmation (complete transactions within million seconds) and high
scalability (attach transactions in parallel) without significantly
compromising security. However, this field still lacks systematic work that
summarises the DAG technique. To bridge the gap, this Systematization of
Knowledge (SoK) provides a comprehensive analysis of DAG-based blockchain
systems. Through deconstructing open-sourced systems and reviewing academic
researches, we conclude the main components and featured properties of systems,
and provide the approach to establish a DAG. With this in hand, we analyze the
security and performance of several leading systems, followed by discussions
and comparisons with concurrent (scaling blockchain) techniques. We further
identify open challenges to highlight the potentiality of DAG-based solutions
and indicate their promising directions for future research.Comment: Full versio