@cafter With respect, it is incorrect that it will take "5 - 10 years" to develop a 4000+ qubit machine. IBM will have one in 2025 (two years from now), making P2PK public addreses (which are not hashed) vulnerable as I said above. So not all of bitcoin will be vulnerable, true, but plenty of it will be, especially because since Taproot, the real unhashed public keys are left exposed after making a transaction so it is correct that the stop gap solution if one is using bitcoin is not to reuse public address, but this does not address the economic / market issue of loss of confidence that would occur if even one P2PK address were compromised. So this is why it is negligence of the highest order for the BTC devs to be continually dismissing this real problem as "FUD" when it would be an easy matter (a soft fork) to replace ECC with something like a hash-based algorithm which is more secure. Just absolute irresponsibility on the part of the bitcoin leadership.

Source that IBM will have 4,158 qubit machine in 2025 (and they have since 2017 always hit their quantum computing roadmaps, so it needs to be taken with the upmost gravity): https://spectrum.ieee.org/ibm-condor

IBM’S CONDOR, THE world’s first universal quantum computer with more than 1,000 qubits, is set to debut in 2023.
The year is also expected to see IBM launch Heron, the first of a new flock of modular quantum processors that the company says
"may" help it produce quantum computers with more than 4,000 qubits by 2025.