Quantum computation represents a threat to many cryptographic protocols in operation today. It has been estimated that by 2035, there will exist a quantum computer capable of breaking the vital cryptographic scheme RSA2048. Blockchain technologies rely on cryptographic protocols for many of their essential sub-routines. Some of these protocols, but not all, are open to quantum attacks. Here we analyze the major blockchain-based cryptocurrencies deployed today -- including Bitcoin, Ethereum, Litecoin and ZCash, and determine their risk exposure to quantum attacks. We finish with a comparative analysis of the studied cryptocurrencies and their underlying blockchain technologies and their relative levels of vulnerability to quantum attacks.
@article{arxiv.2105.01815,
title = {Vulnerability of Blockchain Technologies to Quantum Attacks},
author = {Joseph J. Kearney and Carlos A. Perez-Delgado},
journal= {arXiv preprint arXiv:2105.01815},
year = {2021}
}