I wish people could make requests for supporting information like the grandparent post did without getting this kind of snarky reply. Sometimes questions are just questions, not attacks.
In this case, it would be easiest to simply read the sentence as though there's no snark, as I'd bet it's the correct answer.
Quantum computing is brilliant at certain types of computation, it's not a Singularity-level silver bullet. Simplified to the point of lie, it can transform certain classes of computation by taking shortcuts; the oft referenced Shor's algorithm, for example, can factor a prime in polynomial time, which is immensely faster. [0]
But that wouldn't necessarily be enough to break crypto, as anything that wasn't based on factoring a polynomial would need another algorithm. Also, while fast, the algorithm is not instant nor easy to run: a lot of qubits would be needed, and the current state-of-the-art can't support that level of computation against large numbers without a prohibitive amount of expense (qubits are not naturally stable at room temperature). For comparison, factoring a 1024 bit number would take 1024 qubits together, while only a few have ever operated together under ideal lab conditions (Wikipedia notes IBM's accomplishment factoring 15 with 7 qubits, and notes the number 21 was factored in 2012).
There is a huge amount of work in the pipe, and there's plenty of room to be shocked and amazed by new developments. But it will require innovations that would revolutionize whole industries. This is still very new tech, decades from maturity (though naturally not from commercial early-adoption).
At least, I think that's what tptacek meant. Sorta.
True, but sometimes questions also don't show a whole lot of effort on the part of the asker, and so the answerer is not inclined to put in much of their own. If I'm going to ask a question and want a thorough answer, I try to at least provide a little background on what I already know.
