Your News Feature 'The dreamweaver's abacus' (Nature 452, 803–805; 2008) seems to have been rather carried away by the exciting prospects on offer from the emergent techniques of quantum computing. One thing that even quantum computing can never accomplish is “factoring large prime numbers”. It cannot even factor small ones.
The author is in august company, however, as no less a personage than Bill Gates has had similar visions. In connection with the need to break modern encryption, he wrote: “The obvious mathematical breakthrough would be development of an easy way to factor large prime numbers” (in The Road Ahead; Viking Press, New York, 1995).