On the Security of a Remote Data Possession Checking Scheme in Cloud Storage

Cloud-based outsourced storage alleviates the client´s burden for storage management and maintenance by providing a comparably low-cost, scalable, location-independent platform. Nevertheless, the new conception does triggers lots of security issues. A major concern is how to ensure the integrity of the outsourced data. To deal with the problem, Chen et al. Recently proposed a remote data possession checking (RDPC) scheme based on homomorphic hashing and argued that it was efficient and secure. Unfortunately, through our security analysis, we find out that the scheme is vulnerable to attack by an active adversary. In this paper, we analyze the scheme and point out our attack on their scheme. Through launching the attack, the adversary is able to arbitrarily modify the cloud data without being detected by the data owner in the auditing process. Then we also put forward our solution to fix the problems without losing any desirable features of the original scheme.