数据库中字符型数据的加密及查询

Encryption and Query of Character Data in Database

加密是保护数据库中敏感信息的一种有效手段,如何在保证数据库安全的同时,实现对加密数据的高效查询是目前的一个难题。在此提出一个针对字符型数据的保存顺序加密方案,能直接在加密数据上执行字符串的等值查询;同时,通过构造索引字段储存字符串的结构信息,使子串查询时只需解密部分相关记录,较大地提高了子串查询性能。最后通过实验验证了加密系统的安全性与查询性能的提高。

Encryption is a good means for protecting sensitive data. However, once encrypted, data will no longer be easily queried from exact matches, This paper presents an order-preserving encryption scheme for string data that is robust against ciphertext only, and allows quality query to be directly applied on encrypted data, without decrypting the operands, In addition, to solve the problem of substring query, an additional field that stores the information of character data is constructed, the field can filter some records of being out of relation to the query, and then decrypt the rest records and implement a refine query on the decrypted data. Results of a set of experiments validate the security of this scheme and improvement of the query performance.