Typical Cloud database services guarantee high availability and scalability, but they rise many concerns about data confidentiality. Combining encryption with SQL operations is a promising approach although it is characterized by many open issues. Existing proposals, which are based on some trusted intermediate server, limit availability and scalability of original cloud database services. We propose an alternative architecture that avoids any intermediary component, thus achieving availability and scalability comparable to that of unencrypted cloud database services. Moreover, our proposal guarantees data consistency in scenarios in which independent clients concurrently execute SQL queries, and the structure of the database can be modified
