Certificateless batch verification protocol to ensure data integrity in multi-cloud using lattices

Cloud storage provides flexible On-demand data storage services to users at anytime and anywhere. However, this model of data storage introduces number of new security threats in Cloud due to loss of control over the outsourced data. One of the security challenge in cloud is data integrity protection. In this work, we introduced certificateless batch verification protocol using lattices, which supports integrity checking of multiple data files in cloud environment. Here, third party auditor (TPA) check the integrity of the multiple files stored on cloud servers at a time. By utilising, random masking technique it preserves the privacy against TPA and in case of failure it identifies the invalid proofs using Fibonacci search. The security analysis proves the storage correctness and privacy against the TPA of the proposed method. The experimental results shows that the proposed method decreases computation cost over the TPA approximately 10% compared to individual verification.