Cryptography Challenges for Computational Privacyin Public Clouds

Computational privacy is a property of cryptographic system that ensures the privacy of data (and/or operations) while being processed at an untrusted server. Cryptography has been an indispensable tool for computer security but its readiness for this new generational shift of computing platform i.e. Cloud Computing is still questionable. Theoretical constructions like Fully Homomorphic Encryption, Functional encryption, Server aided Multiparty Computation, Verifiable Computation, Instance Hiding etc. are few directions being pursued. These cryptographic techniques solve Cloud privacy problems at different levels but most of them dont fit well in overall scheme of things. We state the privacy requirements for Cloud offerings in various delivery methods. We discuss the challenges with current cryptographic techniques being pursued by researchers and show that they dont cater to blanket cover these privacy requirements. We urge the need to find generalizations and connections among these isolated techniques. As this might give more insights into the underpinnings of Computational Privacy and lead to better solutions.