Making Smart Contracts Smarter
- Loi Luu, D. Chu, Hrishi Olickel, P. Saxena, Aquinas Hobor
- Computer ScienceIACR Cryptology ePrint Archive
- 24 October 2016
This paper investigates the security of running smart contracts based on Ethereum in an open distributed network like those of cryptocurrencies, and proposes ways to enhance the operational semantics of Ethereum to make contracts less vulnerable.
A Secure Sharding Protocol For Open Blockchains
- Loi Luu, Viswesh Narayanan, Chaodong Zheng, Kunal Baweja, S. Gilbert, P. Saxena
- Computer Science, MathematicsConference on Computer and Communications…
- 24 October 2016
ELASTICO is the first candidate for a secure sharding protocol with presence of byzantine adversaries, and scalability experiments on Amazon EC2 with up to $1, 600$ nodes confirm ELASTICO's theoretical scaling properties.
Demystifying Incentives in the Consensus Computer
- Loi Luu, Jason Teutsch, R. Kulkarni, P. Saxena
- Computer Science, MathematicsConference on Computer and Communications…
- 12 October 2015
This work calls the framework of computation through a scriptable cryptocurrency a consensus computer and develops a model that captures incentives for verifying computation in it and proposes a resolution to the verifier's dilemma which incentivizes correct execution of certain applications, including outsourced computation, where scripts require minimal time to verify.
On Power Splitting Games in Distributed Computation: The Case of Bitcoin Pooled Mining
- Loi Luu, R. Saha, Inian Parameshwaran, P. Saxena, Aquinas Hobor
- Computer Science, EconomicsIEEE Computer Security Foundations Symposium
- 13 July 2015
It is shown that existing pool reward sharing protocols are insecure in the game-theoretic analysis under an attack strategy called the "block withholding attack", which implies that existing pools are insecure, and if the attack is conducted systematically, Bitcoin pools could lose millions of dollars worth in months.
FlyClient: Super-Light Clients for Cryptocurrencies
- Benedikt BĂĽnz, Lucianna Kiffer, Loi Luu, M. Zamani
- Computer Science, MathematicsIEEE Symposium on Security and Privacy
- 1 May 2020
FlyClient is introduced, a novel transaction verification light client for chains of variable difficulty that is efficient both asymptotically and practically and requires downloading only a logarithmic number of block headers while storing only a single block header between executions.
SmartPool: Practical Decentralized Pooled Mining
- Loi Luu, Yaron Velner, Jason Teutsch, P. Saxena
- Computer Science, MathematicsUSENIX Security Symposium
- 16 August 2017
The proposed SMARTPOOL protocol shows how one can leverage smart contracts, autonomous blockchain programs, to decentralize cryptocurrency mining and gives transaction selection control back to miners while yielding low-variance payouts.
A model counter for constraints over unbounded strings
- Loi Luu, Shweta Shinde, P. Saxena, B. Demsky
- Computer ScienceACM-SIGPLAN Symposium on Programming Language…
- 9 June 2014
This work presents a new approach to model counting for structured data types, specifically strings, that can model count for constraints specified in an expressive string language efficiently and precisely, thereby outperforming previous finite-size analysis tools.
Obscuro: A Bitcoin Mixer using Trusted Execution Environments
- Muoi Tran, Loi Luu, M. Kang, Iddo Bentov, P. Saxena
- Computer ScienceIACR Cryptology ePrint Archive
- 3 December 2018
Oscuro is designed to overcome limitations of existing Bitcoin mixers, and offers an indirect deposit mechanism to prevent a malicious service provider from rejecting benign user deposits; and scrutinizes blockchain feeds to prevent deposits from being mixed more than once (thus degrading anonymity) while being eclipsed from the main blockchain branch.
Randomized View Reconciliation in Permissionless Distributed Systems
- Ruomu Hou, Irvan Jahja, Loi Luu, P. Saxena, Haifeng Yu
- Computer ScienceIEEE Conference on Computer Communications
- 16 April 2018
This paper proposes a novel view reconciliation protocol with a time complexity of only $\Theta(\frac{\ln N}{\ln\ln N})$ and aggressively exploit randomization to achieve an exponential improvement.
Smart Contracts Make Bitcoin Mining Pools Vulnerable
- Yaron Velner, Jason Teutsch, Loi Luu
- Computer ScienceFinancial Cryptography Workshops
- 3 April 2017
This paper introduces an attack against mining pools in which a malicious party pays pool members to withhold their solutions from their pool operator, and shows that an adversary with a tiny amount of computing power and capital can execute this attack.
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