@article{zhu2012cooperative,
  title={Cooperative provable data possession for integrity verification in multicloud storage},
  author={Zhu, Yan and Hu, Hongxin and Ahn, Gail-Joon and Yu, Mengyang},
  journal={Parallel and Distributed Systems, IEEE Transactions on},
  volume={23},
  number={12},
  pages={2231--2244},
  year={2012},
  publisher={IEEE}
}