With the advent of cloud storage, more and more users choose to store large amounts of data on the remote cloud server in order to save local storage resources. In recent years, how to verify the integrity of remote stored data in the cloud has been become a hotspot in academia. Although many cloud auditing protocols have been put forward, most of them are based on the assumption that users (individuals or enterprises) and their public/private keys remain constant in the whole process of using cloud storage system, and these schemes cannot dynamically update data in real time. Therefore, this study proposes a lightweight cloud auditing scheme which supports dynamic revocation of users and real-time updating of data. First of all, this scheme allows users to revoke dynamically and efficiently (including the updating of public private keys), multi-use unidirectional proxy re-signature technology is adopted in the stage of revocation, that is, a new user simply needs to calculate the re-signature key instead of downloading data from the cloud to re-sign and then uploading it to the cloud. Secondly, this scheme can realize the data dynamic updating (inserting, deleting, and modifying) in real time by introducing the virtual index into the identification code of data block. Consequently, only the identification code of updated data block changes while the other's remain unchanged when dynamically updating data. Finally, in the stage of re-signature, the cloud server is able to represent a new user to re-sign, and in the stage of auditing, third party audit center can represent the current user to verify the integrity of data in the cloud, which greatly reduce the computational overhead of user and communication overhead of system (lightweight). The security and performance analyses of this study further show that the proposed scheme is secure and efficient.