New order preserving encryption model for outsourced databases in cloud environments

The order of the plaintext remains in the ciphertext, so order-preserving encryption (OPE) scheme is under threat if the adversary is allowed to query for many times. To hide the order in the ciphertext, the only ideal-security OPE scheme (Popa et al., 2013) requires the database server to maintain extra information and realize comparison or range query by user defined functions (UDFs). However, order operations will no longer be performed directly on the ciphertext. It will affect the efficiency and make this scheme to be not suitable for some cases.