Some said we have already protected from the quantum computer. As far as i know, the quantum computer is working to degrade the SHA. This time whole of crypto are using SHA 256 but there was possibility if in the future we will use SHA512 to increase the protection to the quantum computer. CMIIW
SHA-256 is quantum resistant the reason most blockchains are vulnerable to quantum attacks is because the SHA-256 is split in half so each end of the key is not really SHA-256 but 128, dig into it will be a good research.