Comments on "An Efficient Identity-Based Provable Data Possession Protocol with Compressed Cloud Storage"
Lidong Han, Guangwu Xu, Qi You Xie · IEEE Transactions on Information Forensics and Security · 2023
This letter addresses some security issues of an identity-based provable data possession protocol with compressed cloud storage (published in IEEE TIFS, doi:10.1109/TIFS.2022. 3159152). Some serious flaws are identified and an attack to the protocol is designed. This attack is able to recover the ephemeral secret keys from two encrypted blocks with high probability to reveal the original plaintext file completely. Moreover, an adversary can impersonate a data owner to outsource any file to the cloud in a malicious way. The main ingredients of the attack is some classical number theoretic results.