Cloud Computing is the long dreamed vision of computing as a utility, Cloud storage facilitates users to store the data remotely and enjoy the on-demand high quality cloud servers without the burden of local software and hardware systems. By outsourcing the data, users can be comforted from the burden of local data storage and maintenance. By having these many benefits, such a service is also abandon users’ physical control of their outsourced data, which unavoidably posture new security risks towards the accuracy of the data in cloud. In order to address this new problem and further achieve a secure and dependable cloud storage service, we propose in this paper a flexible distributed storage integrity auditing mechanism, utilizing the homomorphic token and distributed erasure-coded data. The proposed design allows users to audit the cloud storage with very lightweight communication and computation cost. The auditing result not only ensures strong cloud storage correctness guarantee, but also simultaneously achieves fast data error localization, i.e., the identification of misbehaving server. Considering the cloud data are dynamic in nature, the proposed design further supports secure and efficient dynamic operations on outsourced data, including block modification, deletion, and append. Analysis shows the proposed scheme is highly efficient and resilient against Byzantine failure, malicious data modification attack, and even server colluding attac