Public auditing scheme for cloud data with user revocation and data dynamics

摘要

Based on proxy re-signature technology and Merkel Hash tree, a new public auditing scheme for cloud data is proposed to solve the problems of dynamic data updating and user revocation. The proxy re-signature key is generated by the current data manager's private key and the public key of the revoked user, which cannot leak any information and realizes transferring of ownership data securely. By using the random masking technique, it can prevent the curious third-party auditor from restoring raw data blocks and ensures privacy of cloud data. In addition, a simple authentication structure is constructed by Merkel Hash tree, which simplifies the data update process and supports the update operations such as inserting, modifying and deleting the cloud data. The analysis results show that the proposed scheme satisfies existential unforgeability, and can resist replay attack and deletion attack.