Computing on Encrypted Data

In modern technologies like cloud computing users outsource computations on their sensitive data to the cloud, while expecting that their data is kept private. This raises the following intriguing possibility: can we keep the users' data encrypted and allow the server to compute on encrypted data without decrypting it and without knowledge of the secret key? Can we keep the users' data encrypted and allow the server to compute only partial information on the data (such as classify the data according to various classification algorithms) without the knowledge of the secret key? Researchers at CIS group are actively studying these questions.