Distributed Query Evaluation over Encrypted Data

The availability of a multitude data sources has naturally increased the need for subjects to collaborate distributed computations, aimed at combining different collections their elaboration and analysis. Due quick pace which collected grow, often authorities collecting owning such datasets resort external third parties (e.g., cloud providers) storage management. Data under control are autonomously encrypted (using encryption scheme key) storage. This makes computations these hard. In this paper, we propose an approach enabling collaborative over in storage, selectively involving also that might not be authorized accessing plaintext when it is considered economically convenient.