Improved Public Auditing System of Cloud Storage Based on BLS Signature

Cloud storage and cloud computing technologies have developed rapidly for a long time, and many users outsource the storage burden of their data to the cloud to obtain more convenient cloud storage services. Allowing users to audit the private data’s integrity has become an additional basic function of the cloud server when providing services. In 2021, based on the BLS signature and automatic blocker protocol, Jalil et al. proposed a secure and efficient cloud data auditing protocol. The protocol can realize public audit, batch audit, data update, and protect data privacy. Moreover, the automatic blocker protocol is used to realize the identity authentication of the auditor. The protocol is relatively novel, innovative, and has a larger use space. However, we found that their scheme had security problems. If the cloud server has thoughts of malicious attack, he can forge the proof that he holds users’ data with stored labels and pass the audit. Referring to the original protocol and being inspired by them, we propose an improved audit protocol. The improved protocol solves the security problem and is more effective.