Though Cloud storage has developed rapidly in recent years, there still exist some problems obviously. Provable Data Possession (PDP) is proposed to solve the problem of data integrity verification at untrusted cloud stores. This study built a new delegation Provable Data Possession (delegation-PDP), which solves problem when the client has no ability to check its remote data. We study the delegation-PDP and use proxy re-encryption to design it. Then we use the improved Elgamal-based algorithm to implement the scheme. Through security analysis and performance analysis, our protocol is provable secure and efficient.
