ProfessorVincent Gramoli

Project Opportunities

Title: Evaluating Blockchain Systems

Summary of opportunity:

The goal of this project is to evaluate the properties of existing blockchain protocols and to propose new building blocks for dedicated applications.

Opportunity synopsis:

A distributed ledger appears as a promising paradigm to transfer assets across users of a peer-to-peer system without requiring any trusted central authority. While its most prominent implementations, Bitcoin and Ethereum [1], were shown effective at managing cryptocurrency publicly among permissionless Internet users, their blockchain abstraction presented anomalies [2] when used to handle ownerships of permissioned users in a private environment [3].  A blockchain is simply a chain of blocks linked to each other in reverse order, from the latest appended block to the initial, also called genesis, block. Blockchain users can invoke transactions to transfer virtual assets from one of their accounts to another account; miners group these new transactions into blocks that they append regularly to the chain. A protocol solving the consensus problem is necessary to guarantee that blocks are totally ordered, hence preventing a block from being appended if it contains transactions that conflict with the transactions of the previous blocks. The goal of this research project is to evaluate the guarantees that blockchain systems offer. This evaluation will consist of listing the necessary properties that a blockchain system should provide for financial applications and will compare the properties offered by classic blockchain implementations as well as new solutions. This will lead to a better understanding of existing blockchain consensus protocols, their strength and limitations, and will help developing new blockchain building blocks tailored for particular applications. [1] G. Wood. Ethereum: A secure decentralised generalised transaction ledger, 2014.[2] Christopher Natoli, Vincent Gramoli. The Blockchain Anomaly. arXiv:1605.05438[3] Vincent Gramoli. On the Danger of Private Blockchains. Workshop on Distributed Cryptocurrencies and Consensus Ledgers (DCCL), 2016.