From the post:
Imagine getting a friend’s advice on a personal problem and being safe in the knowledge that it would be impossible for your friend to divulge the question, or even his own reply.
Researchers at Microsoft have taken a step toward making something similar possible for cloud computing, so that data sent to an Internet server can be used without ever being revealed. Their prototype can perform statistical analyses on encrypted data despite never decrypting it. The results worked out by the software emerge fully encrypted, too, and can only be interpreted using the key in the possession of the data’s owner.
Uses a technique called homomorphic encryption.
The article says 5 to 10 years before practical application, but it was 30 years between its proposal and a formal proof it was even possible. In the 2 or 3 years since that proof, a number of almost practical demonstrations have emerged. Would not bet on the 5 to 10 year time frame.