Bitcoin is not quantum-hard. When quantum computing reaches a certain threshold, bitcoin will lose its uniqueness and collapse.
Could you elaborate which aspect of bitcoin has efficient quantum algorithms? The proof-of-work system requires you to invert hashes and quantum algorithms only give you a quadratic speed up (brute force takes time O(\sqrt{size of range}) rather than O(size of range)). Right now there is no quantum attack on SHA-256 (which is what Bitcoin uses).
There are post-quantum algorithms that are computable on ordinary computers, ...
This sounds interesting, but could you elaborate? What does it mean for a post-quantum algorithm to be computable on ordinary computers?
Could you elaborate which aspect of bitcoin has efficient quantum algorithms?
BitCoin uses public key cryptography for its digital signatures. That in turn relies on the difficulty of factoring large numbers, for which there are efficient quantum algorithms.
Bitcoin actually uses ECDSA for its digital signatures, which relies on the difficulty of calculating discrete logarithms rather than factoring. However I believe that there are efficient quantum algorithms for that, too.
Could you elaborate which aspect of bitcoin has efficient quantum algorithms? The proof-of-work system requires you to invert hashes and quantum algorithms only give you a quadratic speed up (brute force takes time O(\sqrt{size of range}) rather than O(size of range)). Right now there is no quantum attack on SHA-256 (which is what Bitcoin uses).
There are post-quantum algorithms that are computable on ordinary computers, ...
This sounds interesting, but could you elaborate? What does it mean for a post-quantum algorithm to be computable on ordinary computers?