Cloud computing denotes an IT infrastructure where data and software are stored and processed remotely in a data center of a cloud provider, which are accessible via an Internet service. This new paradigm is increasingly reaching the ears of companies and has revolutionized the marketplace of today owing to several factors, in particular its cost-effective architectures covering transmission, storage and intensive data computing. However, like any new tech-nology, the cloud computing technology brings new problems of security, which represents the main restrain on turning to this paradigm. For this reason, users are reluctant to resort to the cloud because of security and protection of private data as well as lack of trust in cloud service providers. The work in this paper allows the readers to familiarize themselves with the field of security in the cloud computing paradigm while suggesting our contribution in this context. The security schema we propose allowing a distant user to ensure a completely secure migration of all their data anywhere in the cloud through DNA cryptography. Carried out experiments showed that our security solution outperforms its competitors in terms of integrity and confidentiality of data.
The data provider (e.g., David) first decides the users (e.g., Alice and Bob) who can share the data. Then, David encrypts the data under the identities Alice and Bob, and uploads the ciphertext of the shared data to the cloud server.
By delegating the generation of re-encryption key to the key authority, the ciphertext size of their scheme also achieves constant.
However, to this end, the key authority has to maintain a data table for each user to store the user’s secret key for all time period, which brings storage cost for key authority.
A cloud service provider has huge storage space, computation resource and shared service to provide the clients. It is responsible for controlling the data storage in outside users’ access, and provides the corresponding contents.
In this module, either Alice or Bob wants to get the shared data, she or he can download and decrypt the corresponding ciphertext. However, for an unauthorized user and the cloud server, the plaintext of the shared data is not available.
In some cases, e.g., Alice’s authorization gets expired, David can download the ciphertext of the shared data, and then decrypt-then-re-encrypt the shared data such that Alice is prevented from accessing the plaintext of the shared data, and then upload the re-encrypted data to the cloud server again.
The objective of the appearance of this paradigm is to process very intensive computer workloads, to sup-ply very large installations for data storage, to provide flexible and highly-performing services and progressive data storage for a daily increasing number of users, to potentially reduce the management and utilization costs, and to satisfy the exploitation of the services and spaces of computer storage available at a provider by clients who are external companies. The methods used to finalize the service between a supplier and an end customer appear in four forms : application, platform, infrastructure, and data. First, the application remains in direct contact with the client. Second, the platform realizes the application.Third, the infrastructure supports the platform. Finally, the data are delivered on request.
Therefore, cloud computing looks a big opportunity for companies, but like any new technology, cloud services bring new security issues.  Data flows across the IP net-works can also carry threats to the system core. Malicious users can take advantage of these security weaknesses to penetrate the system, through the cloud services, and to access the confidential data of any company. Thus, the security problem seems to be a major issue for companies intending to expand in the cloud. It has become one of the main restrains on turning to the cloud. That is why users are unwilling to resort to the cloud due to the security and protection of private data, the operational difficulties or the inability to control information when leaving the perimeter, and the lack of confidence in cloud service providers.
In order to provide an effective solution for the security of the data of remote users against any analysis aimed at their disclosure when migrating to the cloud, we propose a security scheme allowing a remote user to ensure a completely secure migration of all their data anywhere in the cloud through DNA cryptography. The latter is a new and promising field for information security. Indeed, it is possible to benefit from the advantages of biological DNA to store and hide data inside it. In addition, secret information is placed in a molecule of DNA and hidden among other DNA molecules.
The work in this paper allows the readers to familiarize themselves with the field of security in the cloud computing paradigm while suggesting our contribution in this context. The security schema we propose allowing a distant user to ensure a completely secure migration of all their data anywhere in the cloud through DNA cryptography.
The work in this paper has been to develop a security plan taking advantage of combining the benefits given by the recently appearing security mechanisms to provide suf-ficiently robust data confidentiality, while adapting easily to emerging and converging technologies. The solution we have presented in this paper contributes to the data security problem of the cloud paradigm. This solution has the following characteristics: (i) applying a biological system to secure the data of distant users,
(ii)ensuring a protected migration of data in the form of data encrypted into DNA nucleotides forming genetic information,(iii) offering a mechanism based on the DNA test whose aim is to verify the integrity of migrated data during their reception, by means of matching calculation between the hash result of the obtained data and that of the sent ones, and(iv) providing an efficient performance with regard to other previously studied security mechanisms as it ensures a completely secured hosting of their data in the cloud.