20 papers
Steelhead: Interleaving Partially Synchronous and Asynchronous Commit Rules on a Shared DAG
George Danezis, Zeno De Angeli, Philipp Jovanovic +3
Dual-mode consensus protocols are fast when the network is partially synchronous and remain live under asynchrony. We introduce Steelhead, a dual-mode mechanism that composes a par…
Hydrozoan: Latency-Adaptive DAG Consensus under Mixed Byzantine and Crash Faults
Qianyu Yu, Lefteris Kokoris-Kogias, Alberto Sonnino
DAG-based consensus protocols can achieve great throughput and the optimal three-message-delay limit for n = 3f+1 consensus. While two-delay protocols exist, they pay with reduced…
Barnacle: Adaptive Multi-Leader Scheduling for DAG-Based Consensus
George Danezis, Zeno De Angeli, Alexandru Ianov Vitanov +5
In DAG-based consensus, all validators propose blocks concurrently, and designated leader blocks drive transaction commit. Having multiple leader slots per round cuts queuing laten…
Guppy: Efficient Light Clients via Recursive Zero-Knowledge Proofs
George Danezis, Deepak Maram, Arnab Roy +3
Traditional light clients rely on validators committing to the entire blockchain state at every block via a state commitment such as a Merkle tree, allowing clients to verify facts…
Orcaella: Hybrid Fault Tolerance with Client-Selectable Finality Latency
Lefteris Kokoris-Kogias, Alberto Sonnino
Classical partially synchronous state machine replication, as in PBFT, tolerates f Byzantine replicas among n at least 3f+1 using three communication steps per request. Recent prot…
Not All Reads Are Conflicts: A Write-Only Analysis of the Sui Blockchain
Haygen Tsoi, Alberto Sonnino, Philipp Jovanovic
Sui's object-centric data model enables parallel transaction execution, but realised performance is fundamentally bounded by workload contention. Prior empirical analyses of Sui ha…
Remora: Scale-out Deterministic Execution for Smart Contracts
Zhengqing Liu, Alberto Sonnino, Igor Zablotchi +2
Modern blockchains rely on a modular architecture that decouples consensus from execution. Recent advances in consensus algorithms have shifted the bottleneck to the execution laye…
Finding Nemo-Nemo: CFT DAG-based Consensus in the WAN
Rithwik Kerur, Pasindu Tennage, Philipp Jovanovic +3
This paper introduces Nemo-Nemo, a practical crash-fault tolerant (CFT) consensus protocol designed to outperform existing protocols in wide-area networks by bridging design princi…
Tidehunter: Large-Value Storage With Minimal Data Relocation
Andrey Chursin, Lefteris Kokoris-Kogias, Alex Orlov +2
Log-Structured Merge-Trees (LSM-trees) dominate persistent key-value storage but suffer from high write amplification from 10x to 30x under random workloads due to repeated compact…
Sedna: Sharding transactions in multiple concurrent proposer blockchains
Alejandro Ranchal-Pedrosa, Benjamin Marsh, Lefteris Kokoris-Kogias +1
Modern blockchains increasingly adopt multi-proposer (MCP) consensus to remove single-leader bottlenecks and improve censorship resistance. However, MCP alone does not resolve how…
Lifefin: Escaping Mempool Explosions in DAG-based BFT
Jianting Zhang, Sen Yang, Alberto Sonnino +2
Directed Acyclic Graph (DAG)-based Byzantine Fault-Tolerant (BFT) protocols have emerged as promising solutions for high-throughput blockchains. By decoupling data dissemination fr…
Beluga: Block Synchronization for BFT Consensus Protocols
Tasos Kichidis, Lefteris Kokoris-Kogias, Arun Koshy +4
Modern high-throughput BFT consensus protocols use streamlined push-pull mechanisms to disseminate blocks and keep happy-path performance optimal. Yet state-of-the-art designs lack…
BlueBottle: Fast and Robust Blockchains through Subsystem Specialization
Preston Vander Vos, Alberto Sonnino, Giorgos Tsimos +2
Blockchain consensus faces a trilemma of security, latency, and decentralization. High-throughput systems often require a reduction in decentralization or robustness against strong…
Walrus: An Efficient Decentralized Storage Network
George Danezis, Giacomo Giuliari, Eleftherios Kokoris Kogias +4
Decentralized storage faces a fundamental trade-off between replication overhead, recovery efficiency, and security guarantees. Current approaches either rely on full replication,…
Byzantine Consensus in the Random Asynchronous Model
George Danezis, Jovan Komatovic, Lefteris Kokoris-Kogias +2
We propose a novel relaxation of the classic asynchronous network model, called the random asynchronous model, which removes adversarial message scheduling while preserving unbound…
Stingray: Fast Concurrent Transactions Without Consensus
Srivatsan Sridhar, Alberto Sonnino, Lefteris Kokoris-Kogias
Recent advances have improved the throughput and latency of blockchains by processing transactions accessing different parts of the state concurrently. However, these systems are u…
Obelia: Scaling DAG-Based Blockchains to Hundreds of Validators
George Danezis, Lefteris Kokoris-Kogias, Alberto Sonnino +1
Obelia improves upon structured DAG-based consensus protocols used in proof-of-stake systems, allowing them to effectively scale to accommodate hundreds of validators. Obelia imple…
Mahi-Mahi: Low-Latency Asynchronous BFT DAG-Based Consensus
Philipp Jovanovic, Lefteris Kokoris Kogias, Bryan Kumara +3
We present Mahi-Mahi, the first asynchronous BFT consensus protocol that achieves sub-second latency in the WAN while processing over 100,000 transactions per second. We accomplish…
Thunderbolt: Concurrent Smart Contract Execution with Non-blocking Reconfiguration for Sharded DAGs
Junchao Chen, Alberto Sonnino, Lefteris Kokoris-Kogias +1
Sharding has emerged as a critical technique for enhancing blockchain system scalability. However, existing sharding approaches face unique challenges when applied to Directed Acyc…
Pilotfish: Distributed Execution for Scalable Blockchains
Quentin Kniep, Lefteris Kokoris-Kogias, Alberto Sonnino +2
Scalability is a crucial requirement for modern large-scale systems, enabling elasticity and ensuring responsiveness under varying load. While cloud systems have achieved scalable…