Note to recruiters

Note to recruiters: We are quite aware that recruiters, interviewers, VCs and other professionals generally perform a Google Search before they interview someone, take a pitch from someone, et cetera. Please keep in mind that not everything put on the Internet must align directly to one's future career and/or one's future product portfolio. Sometimes, people do put things on the Internet just because. Just because. It may be out of their personal interests, which may have nothing to do with their professional interests. Or it may be for some other reason. Recruiters seem to have this wrong-headed notion that if somebody is not signalling their interests in a certain area online, then that means that they are not interested in that area at all. It is worth pointing out that economics pretty much underlies the areas of marketing, strategy, operations and finance. And this blog is about economics. With metta, let us. by all means, be reflective about this whole business of business. Also, see our post on "The Multi-faceted Identity Problem".

Sunday, August 26, 2012

A breakthrough result in cryptography

Stanford's Craig Gentry's paper on the first ever fully homomorphic encryption scheme has been picked up recently by a mainstream publication. At least, insofar as the American Scientist qualifies. An article by Brian Hayes (thanks, Three Quarks Daily!):

Alice hands bob a locked suitcase and asks him to count the money inside. “Sure,” Bob says. “Give me the key.” Alice shakes her head; she has known Bob for many years, but she’s just not a trusting person. Bob lifts the suitcase to judge its weight, rocks it back and forth and listens as the contents shift inside; but all this reveals very little. “It can’t be done,” he says. “I can’t count what I can’t see.”
Alice and Bob, fondly known as the first couple of cryptography, are really more interested in computational suitcases than physical ones. Suppose Alice gives Bob a securely encrypted computer file and asks him to sum a list of numbers she has put inside. Without the decryption key, this task also seems impossible. The encrypted file is just as opaque and impenetrable as the locked suitcase. “Can’t be done,” Bob concludes again.
But Bob is wrong. Because Alice has chosen a very special encryption scheme, Bob can carry out her request. He can compute with data he can’t inspect. The numbers in the file remain encrypted at all times, so Bob cannot learn anything about them. Nevertheless, he can run computer programs on the encrypted data, performing operations such as summation. The output of the programs is also encrypted; Bob can’t read it. But when he gives the results back to Alice, she can extract the answer with her decryption key.
The technique that makes this magic trick possible is called fully homomorphic encryption, or FHE. It’s not exactly a new idea, but for many years it was viewed as a fantasy that would never come true. That changed in 2009, with a breakthrough discovery by Craig Gentry, who was then a graduate student at Stanford University.  
Here is a link to the incredible result first published in STOC. This is, of course, an absolutely breakthrough result and it has led to a number of subsequent papers which have extended the concept in many ways. There has been a number of subsequent papers on this topic by another rising star, Vinod Vaikuntanathan, who has this to say on a first application of the system.
When I asked Vaikuntanathan what application he thought might be deployed first, he had another suggestion: spam filtering. If you publish a public key and invite correspondents to send you encrypted email, a spammer can take advantage of the key to encrypt advertisements and the other effluvia that fills our mailboxes. Spam-filtering services cannot read and reject the encrypted spam unless you are willing to share your decryption key; homomorphic encryption could solve that problem.