Blockchain-Based Light-Weighted Provable Data Possession for Low Performance Devices

Provable Data Possession(PDP)schemes have long been proposed to solve problem of how to check the integrity of data stored in cloud service without downloading.However,with the emerging of network consisting of low performance devices such as Internet of Things,we find that there are still two obstacles for applying PDP schemes.The first one is the heavy computation overhead in generating tags for data blocks,which is essential for setting up any PDP scheme.The other one is how to resist collusion attacks from third party auditors with any possible entities participating the auditing.In this paper,we propose a novel blockchain-based light-weighted PDP scheme for low performance devices,with an instance deployed on a cloud server.We design a secure outsourced tag generating method for low performance devices,which enables a kind of“hash-sign-switch”two-phase tag computing.With this method,users with low performance devices can employ third party auditors to compute modular exponential operations that accounts for the largest portion of computation overhead in tag generation,without leaking their data content.Chaincodes in blockchain network ensure the correctness of such outsourcing and prevent collusion attacks.The security analysis and performance evaluation prove that our scheme is both secure and efficient.