Research On Query Verification Techniques Of Outsourced Databases

In outsourced databases model, the third-party server may not be completely trusted. If there are no effective security mechanisms provided by server and users can not verify query results, serious consequences are often caused by the results which have been tampered with for the users. Therefore, query authentication techniques in outsourced databases have very broad application prospects and research value.With respect to query verification techniques in outsourced databases, this paper has done the following works.Firstly, this paper analyses existing query verification techniques, which generally exist undesirable signature mutability security issues due to signing crucial data in database using ordinary public key signature schemes, such as RSA. In order to solve this issue, We introduce the idea of designated verifier signature techniques into query answer assurance techniques, and design a designated verifier signature scheme according to the security requirements of outsourced databases. The proposed scheme can overcome the signature mutability security issues incurred by the self-verifiable and transferable properties of traditional signature schemes.Secondly, as far as we know, existing query authentication schemes generally compute verification objects using MHT. However, these techniques based on MHT have following disadvantages:large verification objects, redundant verification procedures and relative low security and so on. So we propose a new solution for outsourced databases. The proposed method has advantages of small additional network load, fast verification, higher security, and being able to locate the tamper with databases at fine grain. We present both theoretical analysis and experimental results to demonstrate that our approach is time and space efficient.Finally, we analyze PMD and Hweehwa query authentication techniques, point out their shortcomings respectively, and propose a secure, super-efficient and privacy-preservation query authentication method based on these two schemes. Both theoretical analysis and experimental results show that our approach is time and space efficient.