Fully Homomorphic Encryption - FHM

A new form of encryption allows you to compute with data you cannot read

The Implications are far reaching - just to mention Cloud Computing...

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. 

Picture Source: Article on americanscientist (link next line)

If you want to know more, read the Article on FHE on americanscientist.org. You can also read the Thesis Paper of the groundwork of FHM  by Craig Gentry here: http://crypto.stanford.edu/craig/craig-thesis.pdf

Update 23.05.2014

now you can actually use it: https://hcrypt.com/