skip to main content

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Arbitrum: Scalable Smart Contracts
We present Arbitrum, a cryptocurrency system that supports smart contracts without the limitations of scalability and privacy of systems previous systems such as Ethereum. Arbitrum, like Ethereum, allows parties to create smart contracts by using code to specify the behavior of a virtual machine (VM) that implements the contract’s functionality. Arbitrum uses mechanism design to incentivize parties to agree off-chain on what a VMwould do, so that the Arbitrum miners need only verify digital signatures to confirm that parties have agreed on a VM’s behavior. In the event that the parties cannot reach unanimous agreement off-chain, Arbitrum still allows honest parties to advance the VM state on-chain. If a party tries to lie about a VM’s behavior, the verifier (or miners) will identify and penalize the dishonest party by using a highly-efficient challenge-based protocol that exploits features of the Arbitrum virtual machine architecture. Moving the verification of VMs’ behavior off-chain in this way provides dramatic improvements in scalability and privacy. We describe Arbitrum’s protocol and virtual machine architecture, and we present a working prototype implementation.  more » « less
Award ID(s):
1717899
PAR ID:
10069458
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
USENIX Security Symposium
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ( , 2020 IEEE International Conference on Blockchain and Cryptocurrency (ICBC))
    null (Ed.)
    The value of cryptocurrencies is highly volatile and investors require fast and reliable exchange systems. In cross-chain transactions, multiple parties exchange assets across multiple blockchains which can be represented as a directed graph with vertexes V as parties and edges E as asset transfers. In a simple form, cross-chain transactions are cross-chain swaps where each edge e transfers an asset that the head of e already owns. However, in general, a cross-chain transaction includes a sequence of exchanges at each blockchain. Further, transactions may have off-chain steps and hence may not be strongly connected. Given a transaction, protocols are desired that guarantee the following property called uniformity. If all parties conform to the protocol, all the assets should be transferred. Further, if any party deviates from the protocol, the conforming parties should not experience any loss. Previous work introduced a uniform protocol for strongly connected cross-chain swaps and showed that no uniform protocol exists for transactions that are not strongly connected. We present a uniform protocol for general cross-chain transactions with sequenced and off-chain steps when a few certain parties are conforming. Further, we prove a new property called end-to-end that guarantees that if the source parties pay, the sink parties are paid. We present a synthesis tool called XCHAIN that given a high-level description of a cross-transaction can automatically generate smart contracts in Solidity for all the parties. 
    more » « less
  2. ( , Distributed computing)
    null (Ed.)
    Modern cryptocurrency systems, such as the Ethereum project, permit complex financial transactions through scripts called smart contracts. These smart contracts are executed many, many times, always without real concurrency. First, all smart contracts are serially executed by miners before appending them to the blockchain. Later, those contracts are serially re-executed by validators to verify that the smart contracts were executed correctly by miners. Serial execution limits system throughput and fails to exploit today’s concurrent multicore and cluster architectures. Nevertheless, serial execution appears to be required: contracts share state, and contract programming languages have a serial semantics. This paper presents a novel way to permit miners and validators to execute smart contracts in parallel, based on techniques adapted from software transactional memory. Miners execute smart contracts speculatively in parallel, allowing non-conflicting contracts to proceed concurrently, and “discovering” a serializable concurrent schedule for a block’s transactions, This schedule is captured and encoded as a deterministic fork-join program used by validators to re-execute the miner’s parallel schedule deterministically but concurrently. We have proved that the validator’s execution is equivalent to miner’s execution. Smart contract benchmarks run on a JVM with ScalaSTM show that a speedup of 1.39× can be obtained for miners and 1.59× for validators with just three concurrent threads. 
    more » « less
  3. ; ; ; ; ; ( , Proceedings of the USENIX Conference)
    Calciu, Irina ; Kuenning, Geoff (Ed.)
    We present RAINBLOCK, a public blockchain that achieves high transaction throughput without modifying the proof-ofwork consensus. The chief insight behind RAINBLOCK is that while consensus controls the rate at which new blocks are added to the blockchain, the number of transactions in each block is limited by I/O bottlenecks. Public blockchains like Ethereum keep the number of transactions in each block low so that all participating servers (miners) have enough time to process a block before the next block is created. By removing the I/O bottlenecks in transaction processing, RAINBLOCK allows miners to process more transactions in the same amount of time. RAINBLOCK makes two novel contributions: the RAINBLOCK architecture that removes I/O from the critical path of processing transactions (txs), and the distributed, multiversioned DSM-TREE data structure that stores the system state efficiently. We evaluate RAINBLOCK using workloads based on public Ethereum traces (including smart contracts). We show that a single RAINBLOCK miner processes 27.4K txs per second (27× higher than a single Ethereum miner). In a geo-distributed setting with four regions spread across three continents, RAINBLOCK miners process 20K txs per second. 
    more » « less
  4. ; ; ; ; ( , 2022 22nd IEEE International Symposium on Cluster, Cloud and Internet Computing (CCGrid))
    In the Internet of Things (loT) era, edge computing is a promising paradigm to improve the quality of service for latency sensitive applications by filling gaps between the loT devices and the cloud infrastructure. Highly geo-distributed edge computing resources that are managed by independent and competing service providers pose new challenges in terms of resource allocation and effective resource sharing to achieve a globally efficient resource allocation. In this paper, we propose a novel blockchain-based model for allocating computing resources in an edge computing platform that allows service providers to establish resource sharing contracts with edge infrastructure providers apriori using smart contracts in Ethereum. The smart contract in the proposed model acts as the auctioneer and replaces the trusted third-party to handle the auction. The blockchain-based auctioning protocol increases the transparency of the auction-based resource allocation for the participating edge service and infrastructure providers. The design of sealed bids and bid revealing methods in the proposed protocol make it possible for the participating bidders to place their bids without revealing their true valuation of the goods. The truthful auction design and the utility-aware bidding strategies incorporated in the proposed model enables the edge service providers and edge infrastructure providers to maximize their utilities. We implement a prototype of the model on a real blockchain test bed and our extensive experiments demonstrate the effectiveness, scalability and performance efficiency of the proposed approach. 
    more » « less
  5. ; ; ; ( , IEEE UEMCON2021)
    The healthcare sector is constantly improving patient health record systems. However, these systems face a significant challenge when confronted with patient health record (PHR) data due to its sensitivity. In addition, patient’s data is stored and spread generally across various healthcare facilities and among providers. This arrangement of distributed data becomes problematic whenever patients want to access their health records and then share them with their care provider, which yields a lack of interoperability among various healthcare systems. Moreover, most patient health record systems adopt a centralized management structure and deploy PHRs to the cloud, which raises privacy concerns when sharing patient information over a network. Therefore, it is vital to design a framework that considers patient privacy and data security when sharing sensitive information with healthcare facilities and providers. This paper proposes a blockchain framework for secured patient health records sharing that allows patients to have full access and control over their health records. With this novel approach, our framework applies the Ethereum blockchain smart contracts, the Inter-Planetary File System (IPFS) as an off-chain storage system, and the NuCypher protocol, which functions as key management and blockchain-based proxy re-encryption to create a secured on-demand patient health records sharing system effectively. Results show that the proposed framework is more secure than other schemes, and the PHRs will not be accessible to unauthorized providers or users. In addition, all encrypted data will only be accessible to and readable by verified entities set by the patient. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email