Issue #75
Paper of the Week:
Paper Title: The Velvet Path to Superlight Blockchain Clients.
TLDR:
Superlight blockchain clients learn facts about the blockchain state while requiring merely polylogarithmic communication in the total number of blocks.
For proof-of-work blockchains, two known constructions exist: Superblock and FlyClient. Unfortunately, none of them can be deployed to existing blockchains, as they require consensus changes and at least a soft fork to implement.
This paper investigates how a blockchain can be upgraded to support superblock clients without a soft fork. It shows that it is possible to implement the needed changes without modifying the consensus protocol and by requiring only a minority of miners to upgrade, a process termed a “velvet fork” in the literature.
It also shows that previous constructions are insecure, and that using velvet techniques to interlink a blockchain can pose insidious security risks.
A novel class of attacks is described, called “chain-sewing”, which arise in the velvet fork setting: an adversary can cut-and-paste portions of various chains from independent temporary forks, sewing them together to fool a superlight client into accepting a false claim.
This work shows how previous velvet fork constructions can be attacked via chain-sewing. Next, it puts forth the first provably secure velvet superblock client construction which is shown secure against adversaries that are bounded by 1/3 of the upgraded honest miner population.
This approach allows proving generic predicates about chains using infix proofs and as such can be adopted in practice for fast synchronization of transactions and accounts.
Authors: Aggelos Kiayias*‡, Andrianna Polydouri†, and Dionysis Zindros†‡,
Affiliations: * University of Edinburgh, † University of Athens, and ‡ IOHK.
Security:
1. Paper Title: A General Framework for the Security Analysis of Blockchain Protocols.
Summary: This paper presents a parsimonious abstraction sufficient for capturing and comparing properties of many well-known permissionless blockchain protocols, simultaneously capturing essential properties of both proof-of-work (PoW) and proof-of-stake (PoS) protocols, and of both longest-chain-type and BFT-type protocols.
Authors: Andrew Lewis-Pye* and Tim Roughgarden†,
Affiliations: * London School of Economics and † Columbia University.
2. Paper Title: Bitcoin–Monero Cross-chain Atomic Swap.
Summary: Atomic swaps between Bitcoin and Monero with two transactions per chain without trusting any central authority, servers, nor the other swap participant.
Authors: Joel Gugger*,
Affiliations: * Independent.
Privacy:
1. Paper Title: Post-Quantum Linkable Ring Signature Enabling Distributed Authorised Ring Confidential Transactions in Blockchain.
Summary: A new post-quantum cryptographic mechanism, called Lattice-based Linkable Ring Signature with Co-Signing (L2RS- CS), which offers a distributed authorization feature to protect electronic wallets.
Authors: Wilson Alberto Torres*, Ron Steinfeld*, Amin Sakzad*, and Veronika Kuchta*,
Affiliations: * Monash University.
Scalability:
No papers.
Proofs:
No papers.
Consensus:
1. Paper Title: A Formally Verified Protocol for Log Replication with Byzantine Fault Tolerance.
Summary: The protocol allows each node to propose entries in a parallel subroutine, and guarantees that correct nodes agree on the set of all proposed entries, without leader election.
Authors: Joel Wanner*, Laurent Chuat*, and Adrian Perrig*,
Affiliations: * ETH Zurich.
2. Paper Title: Economic Proof of Work.
Summary: Extended Proof of Work to be useful and economic.
Authors: Jia Kan*,
Affiliations: * Independent.
Tokenomics:
1. Paper Title: Blockchain as a Confidence Machine: The Problem of Trusts & Challenges of Governance.
Summary: This article draws from the extensive academic discussion on the concepts of “trust” and “confidence” to argue that blockchain technology is not a “trustless technology” but rather a “confidence machine”.
Authors: Primavera De Filippi*, Morshed Mannanc†, and Wessel Reijers‡,
Affiliations: * Université Paris II, † Leiden University, and ‡ European University Institute.
Conferences, Journals, & CFPs:
October 21-23 - The second ACM conference on Advances in Financial Technologies (AFT’20) (New York City)
Conferences’ Videos:
Jobs:
RFPs:
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