probably within the next decade or two but I’m sure it will be pretty expensive at the start nonetheless cardano is developing protocols, check out this forum: Quantum Computing Updates .
In particular IOHK’s whitepapers: https://eprint.iacr.org/2020/107.pdf and https://eprint.iacr.org/2020/186.pdf and Research program to work on hardening Cardano against quantum computers - IOHK Blog
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