Thanks for all of the replies.
I checked out Shor's Algorithm and this wiki article actually talks about it in terms of using it to crack public key encryption - it's an interesting read.
I think this pretty much answers my question. I guess my real question was "would the act of cracking a...
Firstly, I apologise for any lack of understanding, incorrect assumptions or misinterpretations of the very little I know about physics, quantum mechanics & quantum computing. I am not an academic, scientist or mathematician, but a software engineer with an interest in quantum computing and...