Redactable Signature-Based Public Auditing Scheme With Sensitive Data Sharing for Cloud Storage

To guarantee data security, the data owner needs to check the integrity of data stored remotely in the cloud server with the public auditing technique. However, the auditing result will be invalid if the data have been modified dynamically in the process of data anonymization when sharing data to others with sensitive information. In existing solutions, a data sanitizer is needed to anonymize the data and transform the signature. However, such data sanitizers introduce new security risks, and the static anonymous strategy is not flexible to different application scenarios. Therefore, we propose a new scheme based on redactable signature. In our proposed scheme, the cloud server can transform the signature directly without the additional sanitizer while sharing sensitive data. The signature transformation does not influence the integrity checking of the stored data. The signature not only can be used to authenticate the source of sharing data, but can also be used to check the integrity of the stored data in the cloud. Both the security proof and experimental analysis show that our proposed scheme is secure and more efficient than the existing schemes.