Abstract: The cloud computing technology came into existence during the21st century; outsourcing data to cloud service for storage becomes a useful yet efficient trend, which benefits in sparing efforts on data maintenance and management. Nevertheless, since the outsourced cloud storage service is not fully trustworthy, it raises security concerns on how to realize data de-duplication in cloud while achieving integrity auditing. In this work, we study the problem of secure de-duplication on cloud data, also ensuring integrity. Specifically, aiming at achieving both data integrity and de-duplication in cloud, we propose a system, namely D-cloud. D-cloud introduces an auditing entity with maintenance of the cloud, which helps generate hash value before uploading as well as audit the integrity of data having been stored in cloud. Compared with previous work, the computation by user in D-Cloud is greatly reduced during the file uploading and auditing phases. D-cloud is designed realizing the fact that users always want to encrypt their data being uploaded, and enables integrity auditing and secure de-duplication on encrypted data.

Keywords: Secure Auditing, De-Duplicating Data, D-cloud, Integrity, Encrypted Data.