Cloud Auditing with Efficiently Updatable Designated Verifier

Cloud auditing provides a convenient way for users to remotely check the integrity of data stored in the cloud. Public cloud auditing allows any cloud user to perform verification. However, in most real cases, the data owner expects its trusted designated verifier to perform the auditing task. Meanwhile, there are many cases that require updating the verifier, such as contract expiration and auditing costs etc. In traditional auditing scenarios, the CSP recalculates the tags to update the verifier. In order to improve the efficiency, we propose a cloud auditing scheme that can efficiently update the designated verifier based on the trapped collision property of the chameleon hash functions, and illustrate the security and feasibility of the scheme through a proof of security reduction.