Research on ciphertext index method for relational database

Encryption is an important approach of ensuring the data security of relational database. However, most existing encryption algorithms, which are regarded as secure, basically can not guarantee that the order in original text still remains in ciphertext, which brings great efficiency problems during the use of encrypted database; on the other hand, those order-preserving encryption algorithms have difficulties to achieve security. This paper presents a method for database encryption and ciphertext index, in which the conventional security encryption technology was adopted for data encryption; besides, great numbers of exponential algorithms were adopted to generate order-preserving ciphertext index based on the characteristic that it was difficult to obtain the solution with discrete logarithm so as to ensure the efficiency of ciphertext database system.