Cryptanalyses on 'secure and efficient privacy-preserving public auditing scheme for cloud storage'

摘要

Recently, Worku et al. pointed out that Wang et al.'s "privacy-preserving public auditing for data storage security in cloud computing" is insecure and their second work "privacy- preserving public auditing for secure cloud the storage" is inefficient. Thus, they offered a secure and efficient privacy public auditing scheme for cloud storage. They claimed that their system is provably secure in the random oracle model and the computations are effective. However, after cryptoanalysis, we found mat the scheme cannot reach the security goal, it has the existential forgery attack. We, therefore, modify it to include the desired privacy preserving requirement, which is very significant in a privacy-preserving public auditing protocol for cloud storage.