freezing or seizing old addresses as part of a ‘quantum hard fork’ is a non starter
never going to happen, nor should it
quantum risk is theoretical, any protocol changes should do no harm
My understanding is that SHA-256 is weakened by quantum algorithms, but not to an extent that is significant in practice. The situation is not the same as for RSA. It is not automatic that if we build powerful quantum computers, bitcoin breaks. An algorithmic breakthrough is needed. Worth thinking about, but there is already a risk that people break cryptography with classical algorithms. Am I understanding this correctly?