Research On Ciphertext Index Technology Of Database

As the aggregation of information and the core component of computer information system, database security is of vital importance. The root cause of database unsafe is that data are stored by unencrypted data. Existing security measures such as: authorization, access control mechanism, review mechanisms and auditing mechanisms already cannot satisfy the needs of security. The database is deposited by file format, invaders can easily access the database file, and then get valid data information, as long as the security mechanism bypass operating system or use system vulnerabilities. So the to key of protecting data security is encryption. If the data is stored by ciphertext, , illegal user cannot understand ciphertext significance, even data is stolen by their. Henceforth visible, database encryption is very important.Database encryption can solve data security problems, but also brings new difficulties. The main problem is the declines of the system performance. Encrypted data lost original partial order relation of plaintext, make SQL query failure; And the time consume of encryption/decryption operation also reduces the query efficiency, eventually database encryption technology lost practicability and not be putted into use widely.The index technique is often used to accelerate database query. But, usually the establishment and application of index must base on plaintext to ensure the order of the key and improve query efficiency. However original partial order relation of plaintext is damaged in database encryption technology that cause index structure lost the role. How to make the index still play the role of accelerated database query in ciphertext database is more important.This article mainly studied the following several aspects:1. The research background of database encryption technology; the importance and research significance of database encryption and ciphertext index technology; summarizes existing problems of the database encryption index technology. Introduced some basic theory of the database ciphertext index technology. Firstly analyzes the realization of database encryption/decryption mechanism: encryption/decryption mechanism, Chambers library encryption/decryption mechanism and hardware encryption/decryption mechanism of the principle, advantages and disadvantages; Secondly introduces ciphertext database index mechanism: the plaintext for data directly index, address encrypted ciphertext index, dynamic safe ciphertext indexes; Then give the ciphertext database query strategy principles and advantages; At last, analyzed the existing barrels division ciphertext index method.2. Put forward a new index methods, which based on treats the barrel and B+ tree mixed ciphertext index. Firstly analyzes the Database in DAS (Database as a service) model ciphertext the system structure of index Database. To reduce the server to determine the fault examining rate, reduce client required treatment amount of data strategies, as the means of improving the query efficiency. Then give mixing ciphertext index method of how to establish the ciphertext index structure detailed steps. In the final analysis, the method can reflect the wrong examining rate system performance and security.3. Combining based on barrels and B+ tree new hybrid ciphertext index method and relational database itself, we will techniques designed database encryption system model and analysis model of each module in logical structure, and finally achieve a and B+ tree based on barrels of the ciphertext mixed ciphertext index database management system.