If LK-99 works, will existing crypto security be at risk?
Assuming we manage to use the superconductor to create computers 1000x more efficient, or even quantum computers. Will this "break" existing crypto, for example, due to the suddenly insanely high hash rates? Or even by "encryption-breaking" mechanisms?
Ability to compute hashes orders of magnitude faster will no more break crypto than the evolution from CPU mining to GPU mining to FPGA mining to ASIC mining did. So, no that part doesn't break crypto. On the cryptocurrency side, the difficulty self adjusts. On the the password cracking side, it reaffirms the need to use memory-hard hash functions that don't speed up so easily.
How would room temperature superconductors magically make silicon semiconductor CPUs run faster?