The computer science problems that earned Craig Gentry his job at IBM sound a bit like Zen koans. Could Google search the Web without knowing what it was looking for? Can an e-mail filter identify spam without reading it? Could an official count votes in an election without opening a ballot? Those privacy puzzles, as Gentry has shown in an unpublished Ph.D. dissertation, aren't as paradoxical as t
![IBM's Blindfolded Calculator](https://cdn-ak-scissors.b.st-hatena.com/image/square/4e36af98677620fa52d405b20f3b71ce013040d3/height=288;version=1;width=512/https%3A%2F%2Fthumbor.forbes.com%2Fthumbor%2Ffit-in%2F1200x0%2Ffilters%253Aformat%2528jpg%2529%2Fhttps%253A%252F%252Fwww.forbes.com%252Fmedia%252F2009%252F06%252F23%252F0623_forbescover_170x170.jpg)