Design and implementation of an efficient tool to verify integrity of files uploaded to cloud storage

Cloud storage system (CSS) provides storage service through which users can upload their files for getting several benefits like ease of access, less cost and robustness. The uploaded files must be encrypted to achieve confidentiality. These files are replicated across multiple nodes distributed over various geographical boundaries by the CSS provider to ensure robust-ness. But these files may get corrupted unintentionally during transmission or intentionally by malicious users. To ensure the integrity of the uploaded file, an efficient integrity verifier tool is essential. In this paper, the design and implementation of an integrity verifier tool for files uploaded to cloud has been presented. Merkle Hash Tree (MHT) and digital signatures have been used to verify the integrity. The tool has been integrated with Dropbox Cloud Storage Provider and its performance results have been presented.