Dynamic Provable Data Possession with batch-update verifiability

Cloud storage security has drawn more and more concerns in Cloud Computing literatures. The Provable Data Possession (PDP) model has been defined for ensuring the integrity of files on untrusted storages. Since cloud storage is practically not only used for storing static data, the Dynamic Provable Data Possession (DPDP) model has been put forward, in which model, file content can be updated while the storage server is still able to prove the integrity and freshness of the file. In existing DPDP schemes, homomorphic MAC or signature is applied to achieve blockless verification in the course of integrity checking, whereas in the course of update verification, the verification protocol has to be performed for every single block update. In this paper, we develop a batch-update verifiable DPDP mode that verifies a batch of block updates at once to achieve efficiency. We construct our scheme by developing a variant authenticated 2-3 tree to enable data dynamics and batch-update verification. We also employ a BLS-like signature to enable public verification. The simulation shows that our batched scheme achieves great performance improvement on update verification.