A scheme for verifying the integrity of outsourced data

Unauthorized tampering with outsourced data can result in significant losses for both data owner and users. Data integrity therefore becomes an important factor in outsourced data systems. In this paper, we address this problem and propose a scheme for verifying the integrity of outsourced data. We first propose a new authenticated data structure for authenticating membership queries in sets based on accumulators, and then show how to apply it to the problem of verifying the integrity of outsourced data. We also prove that our scheme is secure under the q-strong Diffie- Hellman assumption. More importantly, our scheme has the constant cost communication, meanwhile keeping other complexity measures constant. Compared to previous schemes based on accumulators, our scheme reduces update cost and so improves previous schemes based on accumulators. In addition, the experimental comparison shows that our scheme outperforms the previous schemes.