关键词: 云计算, 外包方案, 可验证, 模指数运算

Abstract:

With the development of cloud computing, more and more people focus on how to outsource the expensive computations to the untrusted cloud servers. Currently, the outsourcing schemes for modular exponentiations are mostly based on two untrusted servers, or the checkability is very small. We propose a new outsourcing algorithm for batch modular exponentiations by using the random permutation. The exponent and the base are both private for the server, and the outsourcer can detect the error with probability close to 1. Compared with the previous algorithms, the proposed one is based on a single server, which realizes the privacy of inputs and increases the checkability of the outsourcing result. Finally, we simulate the proposed algorithm, and the experimental result shows that it can greatly reduce the computational cost for the outsourcer.

Key words: cloud computing, outsourcing algorithm, verifiable, modular exponentiation