Cloud computing is deemed the next-generation information technology(IT) platform, in which a data center is crucial for providing a large amount of computing and storage resources for various service applications with high quality guaranteed. However, cloud users no longer possess their data in a local data storage infrastructure,which would result in auditing for the integrity of outsourced data being a challenging problem, especially for users with constrained computing resources. Therefore, how to help the users complete the verification of the integrity of the outsourced data has become a key issue. Public verification is a critical technique to solve this problem, from which the users can resort to a third-party auditor(TPA) to check the integrity of outsourced data. Moreover,an identity-based(ID-based) public key cryptosystem would be an efficient key management scheme for certificatebased public key setting. In this paper, we combine ID-based aggregate signature and public verification to construct the protocol of provable data integrity. With the proposed mechanism, the TPA not only verifies the integrity of outsourced data on behalf of cloud users, but also alleviates the burden of checking tasks with the help of users’ identity. Compared to previous research, the proposed scheme greatly reduces the time of auditing a single task on the TPA side. Security analysis and performance evaluation results show the high efficiency and security of the proposed scheme. Cloud computing is deemed the next-generation information technology (IT) platform, where a data center is crucial for providing a large amount of computing and storage resources for various service applications with high quality guaranteed. However, cloud users no longer possess their data in a local data storage infrastructure, which would result in auditing for the integrity of outsourced data being a challenging problem, especially for users the constrained computing resources. Therefore, how to help the users complete the verification of the integrity of the outsourced data has become. a key issue. Public verification is a critical technique to solve this problem, from which the users can resort to a third-party auditor (TPA) to check the integrity of outsourced data. Moreover, an identity-based (ID-based) public key cryptosystem would be an efficient key management scheme for certificatebased public key setting. In this paper, we combine ID-based aggregate signature and public veri fication to construct the protocol of provable data integrity. With the proposed mechanism, the TPA not only verifies the integrity of outsourced data on behalf of cloud users, but also alleviates the burden of checking tasks with the help of users’ identity. research, the proposed scheme greatly reduces the time of auditing a single task on the TPA side. Security analysis and performance evaluation results show the high efficiency and security of the proposed scheme.