This Week in Blockchain Research Issue #108

Issue #108


Issue #108

Paper of the Week:

Paper Title: Securing Parallel-chain Protocols under Variable Mining Power.


  1. Several emerging proof-of-work (PoW) blockchain protocols rely on a “parallel-chain” architecture for scaling, where instead of a single chain, multiple chains are run in parallel and aggregated.

  2. A key requirement of practical PoW blockchains is to adapt to mining power variations over time (Bitcoin’s total mining power has increased by a 10^14 factor over the decade).

  3. This paper considers the design of provably secure parallel-chain protocols which can adapt to such mining power variations.

  4. The Bitcoin difficulty adjustment rule adjusts the difficulty target of block mining periodically to get a constant mean inter-block time.

  5. While superficially simple, the rule has proved itself to be sophisticated and successfully secure, both in practice and in theory.

  6. This paper shows that natural adaptations of the Bitcoin adjustment rule to the parallel-chain case open the door to subtle, but catastrophic safety and liveness breaches.

  7. It uncovers a meta-design principle that allows to design variable mining difficulty protocols for three popular PoW blockchain proposals (Prism, OHIE, Fruitchains) inside a common rubric.

AuthorsXuechao Wang*, Viswa Virinchi Muppirala†, Lei Yang‡, Sreeram Kannan†, and Pramod Viswanath*.

Affiliations: * University of Illinois Urbana-Champaign,† University of Washington at Seattle, and ‡ MIT CSAIL.


1. Paper Title: Reentrancy Vulnerability Identification in Ethereum Smart Contracts.

Summary: A framework that combines static and dynamic analysis to detect Reentrancy vulnerabilities in Ethereum smart contracts.

Authors: Noama Fatima Samreen* and Manar H. Alalfi*,

Affiliations* Ryerson University.

2. Paper Title: T-Cash: Transferable Fiat Backed Coins.

Summary: A transferable electronic cash scheme using blockchain technology which allows users to continuously reuse coins within the system.

Authors: Hitesh Tewari*,

Affiliations* Trinity College Dublin.


1. Paper Title: Holistic Privacy and Usability of a Cryptocurrency Wallet.

Summary: The problems associated with the usability of cryptocurrency wallets, such as those used by ZCash, for end-users.

Authors: Harry Halpin*,

Affiliations* Nym Technologies.


1. Paper Title: A DLT-based Smart Contract Architecture for Atomic and Scalable Trading.

Summary: A protocol that combines a hierarchical smart contract infrastructure with state channels to increase scalability of an underlying DLT system.

Authors: Jan Kalbantner*, Konstantinos Markantonakis*, Darren Hurley-Smith*, Carlton Shepherd*, and Benjamin Semal*,

Affiliations* University of London.


1. Paper Title: An Algebraic Framework for Universal and Updatable SNARKs.

Summary: A new information theoretic inter- active proof system in which the prover shows that a vector has been sampled in a subspace according to the verifier’s coins.

Authors: Carla Rafols*† and Arantxa Zapico*†

Affiliations* Pompeu Fabra University and † Cybercat.


1. Paper Title: Making Synchronous BFT Protocols Secure in the Presence of Mobile Sluggish Faults.

Summary: This work investigates the support for mobile sluggish faults in existing synchronous protocols such as Dfinity, Streamlet, Sync HotStuff, OptSync and the optimal latency BFT protocol.

Authors: Justin Kim*, Vandan Mehta†, Kartik Nayak‡, and Nibesh Shrestha§,

Affiliations* Montgomery High School, † Rutgers University, ‡ Duke University, and § Rochester Institute of Technology.


1. Paper Title: Cyclic Arbitrage in Decentralized Exchange Markets.

Summary: Cyclic arbitrages in Decentralized Exchanges (DEXes) of cryptocurrencies with transaction-level data on Uniswap V2, observing 285,127 cyclic arbitrages over eight months.

AuthorsYe Wang*, Yan Chen†, Shuiguang Deng†, and Roger Wattenhofer*,

Affiliations: * ETH Zurich and † Zhejiang University.

2. Paper Title: Lightning Network Economics: Channels.

Summary: This paper (i) identifies conditions for two parties to optimally establish a channel, (ii) finds explicit formulas for channel costs, (iii) obtains the optimal collaterals and savings entailed, and (iv) derives the implied reduction in congestion of the blockchain. 

AuthorsPaolo Guasoni*, Gur Huberman†,  and Clara Shikhelman‡,

Affiliations: * Dublin City University, † Columbia Business School, and ‡ Chaincode Labs.

3. Paper Title: An economic theory of blockchain foundations.

Summary: The treasury foundations manage is a moat to raise the cost of exit or forking because the benefit of the fund is only available to those who stay with the chain.

AuthorsDarcy Allen*, Chris Berg*, Sinclair Davidson*, Trent MacDonald*, and Jason Potts*

Affiliations: * RMIT University.

Upcoming Events:


Thanks to our sponsor

Protocol Labs

Protocol Labs is an open-source research, development, and deployment laboratory. Projects include IPFS, Filecoin, libp2p, and many more. Protocol Labs aims to make human existence orders of magnitude better through technology. 

The internet is humanity’s superpower, and they’re making it more dependable, equitable, and secure. Join the Protocol Labs team!

This newsletter is for informational purposes only. This content does not in any way constitute an offer or solicitation of an offer to buy or sell any investment solution or recommendation to buy or sell a security; nor it is to be taken as legal, business, investment, or tax advice. In fact, none of the information in this or other content on zk Capital should be relied on in any manner as advice. None of the authors, contributors, or anyone else connected with zk Capital, in any way whatsoever, can be responsible for your use of the information contained in this newsletter.