The authors give the first formal model of BIP70 and formalise the refund address security goals for the protocol. They confirm that the Payment Protocol is vulnerable to an attack violating the refund address authentication security goal and present a concrete protocol revision proposal.
Paolo Modestia Teesside University), Siamak F. Shahandashtib (University of York), Patrick McCorry (PISA Research), Feng Haod (University of Warwick)
The authors show that there is a statistically significant correlation between the profitability of mining and the total hash rate. They present a theoretical analysis showing that selfish mining under elastic hash supply leads either to the collapse of a chain or to a stable equilibrium depending on the attacker’s initial share.
Yoko Shibuya (NTT Research), Go Yamamoto (NTT Research), Fuhito Kojima (NTT Research), Elaine Shi (Cornell), Shin'ichiro Matsuo (Georgetown), Aron Laszka (University of Houston)
The authors summarize bribing attacks and similar techniques that leverage on programmatic execution and verification under the term algorithmic incentive manipulation (AIM) attacks. They present several research gaps and opportunities that warrant further investigation- particularly no- and near-fork attacks.
Aljosha Judmayer (SBA Research, Uni Wien), Nicholas Stifter (SBA Research, Uni Wien), Alexei Zamyatin (Imperial College London), Itay Tsabary (Technion, IC3), Ittay Eyal (Technion, IC3), Peter Gaži (IOHK), Sarah Meiklejohn (UCL), Edgar Weippl (Uni Wien)
The authors present a new method of bribing attacks on cryptocurrencies, Pay-To-Win (P2W), which is capable of facilitating double-spend collusion across different blockchains financed out-of-band. This technique can also be used to specifically incentivize transaction exclusion or (re)ordering. They use smart contracts to render the payment and receipt of bribes trustless. Their approach is approximately one order of magnitude cheaper than comparable bribing techniques.
Aljosha Judmayer (SBA Research, Uni Wien), Nicholas Stifter (SBA Research, Uni Wien), Alexei Zamyatin (Imperial College London), Itay Tsabary (Technion, IC3), Ittay Eyal (Technion, IC3), Peter Gaži (IOHK), Sarah Meiklejohn (UCL), Edgar Weippl (Uni Wien)
The authors develop a model of stable assets, including non-custodial stablecoins backed by cryptocurrencies. They derive fundamental results about dynamics and liquidity in stablecoin markets, demonstrate that these markets face deleveraging feedback effects that cause illiquidity during crises and exacerbate collateral drawdown, and suggest design improvements. They also introduce new attacks that exploit arbitrage-like opportunities around stablecoin liquidations.
Ariah Klages-Mundt and Andrea Minca (Both Cornell)
The authors propose a BFT SMR protocol that achieves optimal linear cost per decision under good networks and leaders, optimal quadratic cost per decision under bad networks, and remains always live.
Rati Gelashvili (Novi), Lefteris Kokoris-Kogias (Novi and IST Austria), Alexander Spiegelman (Novi), Zhuolun Xiang (UIUC)
