A Study Of Identity Encryption Method Application In Composite Documents Secure Deletion

With the rapid development of cloud computing technology, traditional mono document is being replaced by composite documents. In the cloud environment composite documents is bearing cloud service and complicated work-flows which with different private information. Publicly Posted Composite Documents (PPCD) is a new composite documents structure and visit mechanism, was proposed in recent years to offer and carry out different visit control. But after the expiration of PPCD, because of the leakage of secure deletion mechanism lead to privacy information disclosure will lead to serious results and losses, this issue has caused widely attention of academic. At the same time, as PPCD supports multiple composite documents work-flow participants operation, and can span multiple unsecured field and transmit through unsecured channel. But in the cross-domain transmission or cross cloud data storage system etc, which all produce many data multiple replicas, so propose a bigger challenge to data safely delete. According to the above problem, this paper mainly research work are as below:Firstly, to propose Secure Self-Destruction Scheme for Publicly Posted Composite Documents with Identity-based Encryption(ICDSS) for the problem of secure deletion after the expiration of PPCD. And the scheme is combination with multiple security levels, Identity-based encryption, symmetrical encryption, object storage system and PPCD, So the ICDSS can solve the the security problem of PPCD during its whole life-cycle. At the same time we analyze the security and function of this scheme. Analysis proves that the scheme is viable.Secondly, through layering thoughts, this paper proposes another secure deletion scheme--Secure Self-Destruction Scheme for Publicly Posted Composite Documents with Hierchical Identity-based Encryption(HICDSS) for the problem of single point failure that probably happens in the scheme of ICDSS which is caused by Private Key Generate (PKG) overloaded and easily becoming attack target of potential enemies. Meanwhile, this paper analyses the security and efficiency problems of two proposal schemes. The analysis proves that the scheme of HICDSS is more effective and more secure.Thirdly, to build the associate model of data multiple replicas based on logic file name and propose the strategy of secure deletion of data multiple replicas for the problem of there being replicas of ciphertext in the expiration of PPCD, which is saved in the cloud storage system. This provides thoughts for secure deletion of data multiple replicas.The schemes in this paper can provide effective solutions to solve the problem of secure deletion of PPCD after it is expired. Meanwhile it can provide solution strategy for the secure deletion and associate of data multiple replicas saving in the cloud storage system.