Cloud storage auditing guarantees the security of data stored in the cloud, enabling data owners to easily verify the integrity of data. However, a vast amount of data in the cloud can lead to significant computational overhead during cloud storage auditing when verifying data integrity and modifying data ownership. To solve this problem as well as provide practical solutions, this study proposes a dynamic auditing scheme for cloud storage with efficient data ownership sharing. An efficient validation structure is constructed to aggregate information for data verification, avoiding a large number of bilinear pairing operations that incur high computational costs. An efficient mechanism for data ownership sharing is designed based on the chameleon hash function’s ability to generate new collisions. It allows updating the secret key of the corresponding user for shared data ownership without modifying the ciphertexts stored in the cloud. In addition, the proposed scheme achieves fine-grained data sharing, encrypted data auditing, and dynamic data modification. The security and performance analyses show that the proposed scheme ensures the security of data in the cloud without affecting its performance, which means it is a practical scheme.