An efficient provable data possession based on elliptic curves in cloud storage

With the widespread use of cloud computing and cloud storage, how to ensure the authenticity of data in remote storage is becoming a severe problem. Provable data possession (PDP) is a technique for a client to verify whether an untrusted server possesses the original data. Moreover, for the requirement of efficiency and instantaneity, clients need to verify the authenticity of stored data without having the server retrieving and accessing the entire file. There are many PDP models to resolve these issues. In 2007, G. Ateniese et al. firstly defined a sampling model named S-PDP, which is regarded as "state-of-the-art" in this field. In terms of efficiency, we found that S-PDP can be improved by utilizing elliptic curve cryptography. Based on this observation, we propose a more efficient scheme which we call EC-PDP. We also implement EC-PDP and compare the performance with S-PDP. In our scheme, the metadata of the client is reduced by 84%, and the computation complexity which consists of the computational cost of pre-processing, generating a proof and verification is reduced by 13% approximately.