IC3: Advancing the science and applications of blockchains

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by Ari Juels on July 20, 2022
Bitcoin and blockchains - the technology that makes cryptocurrencies such as Bitcoin possible - have become inescapable phenomena in finance and even popular culture. Despite their rise in popularity, though, there is considerable bewilderment around blockchains and their capabilities. In this talk, Ari Juels, the Weill Family Foundation and Joan and Stanford I. Weill Professor at Cornell Tech and Co-Director of the Initiative for CryptoCurrencies and Contracts (IC3), will aim to demistify this intriguing technology. He will explain how blockchains mean much more than Bitcoin and indeed how blockchain-based digital apes may be harbingers of our future in leisure and the arts. We hope to see you at this virtual event.
by Youer Pu, Lorenzo Alvisi and Ittay Eyal on June 21, 2022
The Nakamoto consensus protocol works in a permissionless model, where nodes can join and leave without notice. However, it guarantees agreement only probabilistically. Is this weaker guarantee a necessary concession to the severe demands of supporting a permissionless model? We show that, at least in a benign failure model, it is not. We present Sandglass, the first permissionless consensus algorithm that guarantees deterministic agreement and termination with probability 1 under general omission failures. Like Nakamoto, Sandglass adopts a hybrid synchronous communication model, where, at all times, a majority of nodes (though their number is unknown) are correct and synchronously connected, and allows nodes to join and leave at any time.
by Weizhao Tang, Lucianna Kiffer, Giulia Fanti and Ari Juels on May 25, 2022
In traditional financial systems, time equals money and network latency - i.e., the time for messages to travel in a network - has an outsized impact. Recently, network latency has become critical in blockchain peer-to-peer (P2P) networks as well. Among other impacts, low-latency connections in P2P networks can advantage arbitrageurs by giving them the ability to exploit the trades of other users for financial gain. In this blog post, we summarize a recent paper of ours that explores P2P network latency. We present Peri, a practical strategy that selects peers with low latencies from a local view of the P2P network. we demonstrate how startegic agents, i.e., self-interested P2P network actors, can use Peri to manipulate network latency to their advantage.
by Sarah Allen, Ari Juels, Mukti Khaire, Tyler Kell and Siddhant Shrivastava on April 25, 2022
Fine artists exercising unprecedented control of their own markets, high tech art, cartoon images of rocks selling for millions of dollars, scams, cult-like followings - the NFT market has it all! In this post, we will briefly survey the traditional art market abd the NFT fine art market. The convergence of these things - NFT technology and the traditional art market - leads us to make predictions for the future of the market and technology.
by James Grimmelmann, Yan Ji and Tyler Kell on March 21, 2022
Many NFT and DAOs are designed to provide new or more convenient ways to own and sell creative works. Beeple's EVERYDAYS - The First 5000 Days sold at auction for $69 million. Some observers think that the Bored Ape Yacht Club's spectacular rise is due to its permissive copyright approach. Some artists and developers are diving in head-first.
by Ittay Eyal and Ittai Abraham on March 07, 2022
The Selfish mining attack against blockchain protocols was discovered and formalized in 2013 by Eyal and Sirer (also see our blog post). The Bitcoin community has mentioned similar types of attacks in 2010. This attack remains a vulnerability of all operational blockchains we are aware of. For Bitcoin's blockchain algorithm (under reasonable network assumptions), a coalition controlling over 1/4 of the mining power can improve its revenue using this attack.
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August 29-31, 2022
This conference focuses on technical innovations in the blockchain ecosystem, and brings together researchers and practioners working in the space. We are interested in the application of cryptography, decentralized protocols, formal methods, and empirical analysis, to improving the security and scalability of blockchain deployments. We aim to foster collaboration among practitioners and researchers working on blockchain protocol development, cryptography, distributed systems, secure computing, crypto-economics, and economic risk analysis.
August 1-7, 2022
Join us for the 7th Annual IC3 Blockchain Camp! This 7-day experience will be hosted in-person on the Cornell Campus in Ithaca, NY. Our camp technical committee of Surya Bakshi, Tyler Kell and Patrick McCorry is preparing another immersive coding and learning experience.
April 29, 2022 -May 1, 2022
Cornell FinTech Club (CFT), the first all-encompassing fintech club for undergraduates at Cornell University, is hosting a blockchain hackathon (NFTs and more) from April 29 to May 1, 2022 sponsored by Ava Labs, Fintech at Cornell, and The Initiative for CryptoCurrencies and Contracts (IC3). This hackathon aims to inspire participants to create blockchain innovations by introducing fintech concepts and developing with Avalanche, Ava Labs' smart contracts blockchain platform. Attendees can mentor, judge, or host/speak at a workshop/event and Cornell undergraduate students only can hack in teams for prizes. With workshops, a $6k+ prize pool, multiple challenges, food, swag, social and corporate events, attendees and hackers will experience a fun, innovative weekend. Want to attend or hack at the 2022 Cornell FinTech Club Avalanche Hackathon? Please fill out this interest form.
Monday December 13, 2021
The attempt to modernize oversight of America's financial markets and the simultaneous rise of bitcoin, cryptocurrencies, and the digital dollar are disrupting financial services as we know them. This roundtable will examine the potential for crypto/blockchain networks to transform the financial sector and what that means for consumers and institutions.
October 6-7, 2021
The goal of this event is to introduce Protocol Labs Research's newly formed ConsensusLab to its future partners and to establish a workshop-style venue to bottstrap scientific exchange across a wider community of shared interests. We invite contributions from current and prospective collaborators, as well as from all researchers in the field.
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Featured Projects

Ponyta: Foundations of Side-Contract-Resilient Fair Compliance

Fair exchange is a fundamental primitive for blockchains, and is widely adopted in applications such as atomic swaps, payment channels, and DeFi. Most existing designs of blockchain-based fair exchange protocols consider only the users as strategic players, and assume honest miners. However, recent works revealed that the fairness of commonly deployed fair exchange protocols can be completely broken in the presence of user-miner collusion. In particular, a user can bribe the miners to help it cheat - a phenomenon also referred to as Miner Extractable Value (MEV). We provide the first formal treatment of side-contract-resilient fair exchange. We propose a new fair exchange protocol called Ponyta, and we prove that the protocol is incentive compatible in the presence of user-miner collusion. In particular, we show that Ponyta satisfies a coalition-resistant Nash equilibrium. Further, we show how to use Ponyta to realize a cross-chain coin swap application, and prove that our coin swap protocol also satisfies coalition-resistant Nash equilibrium. Our work helps to lay the theoretical groundwork for studying side-contract-resilient fair exchange. Finally, we present practical instantiations of Ponyta in Bitcoin and Ethereum with minimal overhead in terms of costs for the users involved in the fair exchange, thus showcasing instantiability of Ponyta with a wide range of cryptocurrencies. For further details, please check out our Projects Page.

Fair exchange
Nash equilibrium

More projects:

  • F3B: A Low-Latency Commit-and-Reveal Architecture to Mitigate Blockchain Front-Running
  • Smart Contracts: Exploring Security Practices of Smart Contracts Developers
  • Baxos: Backing off for Robust and Efficient Consensus
  • WeRLman: To Tackle Whale (Transactions), Go Deep (RL)
  • P2P: Strategic Latency Reduction in Blockchain Peer-to-Peer Network
Even more projects...