The Blockchain@X research center was created by the Ecole polytechnique with the support of Capgemini, Nomadic Labs and Caisse des Dépôts. It brings together researchers in computer science and economics whose research focus on blockchains and associated technologies.


Blockchain@X combines academic excellence with business & tech leadership to foster blockchain innovation.


Proceedings Tokenomics 2021

Tokenomics is an international forum for theory, design, analysis, implementation and applications of blockchains and smart contracts. The goal of the conference is to bring together economists, computer science researchers and practitioners working on blockchains in a unique program featuring outstanding invited talks and academic presentations.
  • Publication date: 10/2022
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Optimal Cryptocurrency Design: Seigniorage versus Transaction Fees

This paper studies how transaction fees and seigniorage, equivalent to inflation in the cryptocurrency setting, affect miner incentives and trade congestion. Each cryptocurrency miner chooses how many new transactions to group into the next block of transactions that the miner competes to validate. The successful miner earns (i) transaction fees from traders seeking to record their transfers and (ii) the new cryptocurrency units or seigniorage created by block validation. Pro rata transaction fees encourage miners to include more transactions per proposed block but larger blocks transmit more slowly, raising the risk of invalidation. Raising the seigniorage to fee ratio reduces the number of transactions recorded per block. When miners choose small blocks, congestion levels rise and eventually trade breaks down, making the cryptocurrency unviable. This requires a minimal ratio of seigniorage to fees. Optimal cryptocurrency design maximizes trade efficiency subject to miner participation constraints and these miner incentives.
Keywords: Cryptocurrency miners, blockchain, congestion, seigniorage.
JEL Codes: E42, C73, D47.
  • Author:Michele Fabi
  • Publication date: 02/2022
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Efficient multivariate low-degree tests via interactive oracle proofs of proximity for polynomial codes

In STARK-like zero -knowledge proofs, like those of the Starware company, the major algorithmic and mathematical breakthrough which enables such great performance in applications is the invention of very efficient "low degree test" of univariate polynomials. Our work enables to perform such low degree test for multivariate polynomials, with the same efficiency. This is a first layer, and we think it can lay ground for still more optimization of STARKs.
  • Author:Sarah Bordage, Jade Nardi, Daniel Augot
  • Publication date: 01/2022
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Les rollups : un mécanisme puissant de passage à l’échelle

  • Publication date: 12/2022
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We provide a series of courses at the Ecole polytechnique for students and professionals that wish to foster their understanding of DLT and blockchains.

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The Blockchain@X Research Center is directed by Daniel Augot and Julien Prat. It is composed of researchers and Ph.D. students at the Ecole Poytechnique as well as of associate researchers dedicated to these four areas of expertise :

Distributed Algorithms
Formal proof
Formal proof
Incentives & Governance
Incentives & Governance

Meet our Team