This question already has an answer here:
@PieterWuille wrote in another thread:
"" The hashing algorithm is probably the most quantum-resistant piece of cryptography right now in Bitcoin. Barring any specific breaks, SHA256 and RIPEMD160 are as quantum-resistant as hash functions can be (there is an inevitable square-root speedup that applies to any hash function). Much more can be said about the quantum resistance of digital signatures. – Pieter Wuille Mar 5 at 0:03 ""
I would like to ask for more precise information if possible:
Which precise parameters of bitcoins blockchain would be susceptible to quantum attacks (Pieter mentioned "signatures", but what else)? And what could be the potential impact if those parameters (signature, etc.) were successfully attacked? (one transaction could be blocked, the entire blockchain controlled, etc...which practical effects?)
-And what could be ways to prevent attacks on those parameters? Any ideas circulating among btc dev community on how to "adjust" those parameters?
- Or is the current consensus among the community to rather wait for the world till they provide new crypto schemes which are quantum proof (for example waiting for the NIST Post-Quantum Crypto Competition) ...