[Cryptography] Post Quantum Crypto

[Krisztián Pintér]

i would like to hear the opinion of someone who actually knows some
details.

to my knowledge, most quantum experiments require many many repeated
attempts, simply because the detection rate is poor. the more stuff we
need to measure, the less chance a reading will be the actual result,
and not blank or noise. like for example if detecting photon
polarization has detection rate of 1%, then a simultaneous pair
detection will have 0,01%, and a triple detection will have 0,0001%.

1, is this the case with d-wave and quantum computers in general?

2, if so, is the detection rate / repeat number changes exponentially
with the number of qubits, like in the photon example above?

because if these are true, the detection probability might be the main
issue with QC. it can compute its thing in O(1), but we need O(2^n)
measurements, which is not an achievement over classical.