Bilinear Aggregate Signature and PDP Encryption in Audit Service for Cloud Storage

Cloud-based outsourced storage relieves the client’s burden for storage management and maintenance by providing a comparably low-cost, scalable, location-independent platform. However, the fact that clients no longer have physical possession of data indicates that they are facing a potentially formidable risk for missing or corrupted data. Provable data possession (PDP), which is a cryptographic technique for verifying the integrity of data without retrieving it at a distrusted server, can be used to realize audit services. We prove that our construction holds these properties based on the computation Diffie–Hellman assumption and the rewind able black-box knowledge extractor. We also propose an efficient mechanism with respect to probabilistic queries and periodic verification to reduce the audit costs per verification and implement abnormal detection timely. In addition, we present an efficient method for selecting an optimal parameter value to minimize computational overheads of cloud audit services. Our experimental results demonstrate the effectiveness of our approach. This kind of outsourced storage services in clouds have become a new profit growth point by providing a comparably low-cost and scalable.