The invention relates to a general 
database transparent 
encryption system and belongs to the fields of 
information security and 
database encryption technologies. According to the 
system, first, an existing data table is subjected to 
encryption transformation, the table where an encrypted field P1 exists is recorded as T1, and a 
ciphertext index field I1 is established based on the encrypted field P1; and then, the content of a to-be-encrypted field is mapped to a Hash value based on an order-preserving 
Hash function, and the Hash value is used as an index value to be interposed into the field I1. The 
system comprises an 
SQL gateway module and an encryption plug-in module, wherein the 
SQL gateway module is used for receiving and 
rewriting an 
SQL statement sent by a 
client, sending the SQL statement to a 
database server and forwarding a result returned by the 
database server to the 
client; and the encryption plug-in module is located in a database, mainly comprises a series of user-defined functions (UDFs) and achieves encryption, decryption and 
ciphertext indexing functions according to the SQL statement obtained after 
rewriting. Compared with the prior art, the truly-general 
database encryption system is realized.