Good thing noone has managed to make quantum computers work, and not for the lack of trying. I remember in 2007 when we hit a single core wall everyone was screaming that quantum computers are the next step and current technology halted. well no, we just got better at it. Sure, someday quantum computers may be a reality. not today though. Though technically there is one, who can calculate 2+2 and not much else, but its a proof of concept.
As far as breaking encryption i think their better off investing into a supercomputer. If we have a computer that fits in your palm able to crack a 8 digit/letter passwords in under 30 minutes, we have computers that can crack harder ones in similar fashion. and that was last years codecracking show, or well, two years ago now since we are in 2014 now.