全委托的公共可验证的外包数据库方案

为解决可验证外包数据库方案存在的预处理阶段开销较大及不支持公共可验证的问题，提出了一个全委托的公共可验证的外包数据库模型.给出了模型的架构及交互流程，对模型进行了形式化定义，并给出了模型的正确性定义和安全性定义.利用双线性映射及可验证外包模幂运算协议，构建了一个全委托的公共可验证外包数据库方案，且给出了各个算法的详细描述，证明了方案的正确性和安全性.其安全性可规约为BDHE （bilinear diffie-hellman exponent）难题.与现有方案及不进行全委托计算的方案相比，全委托的公共可验证的外包数据库方案基于可验证外包模幂运算，将大量模幂运算外包给云处理，减小了数据拥有者的开销.理论与实验分析表明：该方案数据拥有者在预处理阶段所需的代价更低，效率更高，适于实际应用.此外，验证过程无需私钥参与，实现了公共可验证.

Publicly Verifiable Outsourced Database with Full Delegations

To solve the problem of high preprocessing cost and public verifiability in the verifiable outsourced database schemes, a publicly verifiable outsourced database with full delegation is proposed. The architecture and the definition of security and correctness of the model are present. Based on the bilinear map and verifiable outsourced modular exponentiations protocol, a publicly verifiable outsourced database scheme with full delegation is constructed, and each algorithm is designed in detail. The rigorous security proof is presented under the bilinear Diffie-Hellman exponent (BDHE) problem. Compared with performing the protocol without full delegation scheme and the existing schemes, the data owner in publicly verifiable outsourced database with full delegations scheme outsources more operations to the cloud because of the application of the verifiable outsourced modular exponentiation operation. The theoretical analysis and simulation confirm that the cost of the proposed scheme is lower in the preprocessing phase, which makes it more efficient and practical. In the verification phase, any user can verify the result since the verification algorithm does not take any secret key as input. Therefore, the proposed scheme achieves public verifiability.