Biblio

In recent days cloud domain gains a lot of user attention in order to store and access the data from remote locations connected through the internet. As it is generally known that all the sensitive data come from remote locations will be stored in the centralized storage medium and then try to access the data from that centralized storage space controlled by the cloud server. It is facing a problem like there is no security for the data in terms of user authorization and data authentication from the centralized storage location. Hence, it is required to migrate for a new storage procedure like Decentralized storage of cloud data in which the systems that do not rely on a central authority, so that the collusion resistance can be avoided by maintaining a global identifier. Here, the term de-centralized access means granting multi authorities to control the access for providing more security for the sensitive data. The proposed research study attempts to develop a new scheme by adding a global identifier like Attribute Authority (AA) for providing access keys for the data users who wish to access the sensitive information from the cloud server. The proposed research work attempts to incorporate the composite order bilinear groups scheme for providing access facility for the data users and provide more security for the sensitive data. By conducting various experiments on the proposed model, the obtained result clearly tells that the proposed system is very efficient to access the data in a de-centralized manner by using a global identifier.

In previous multi-authority key-policy attribute-based Encryption (KP-ABE) schemes, either a super power central authority (CA) exists, or multiple attribute authorities (AAs) must collaborate in initializing the system. In addition, those schemes are proved security in the selective model. In this paper, we propose a new fully secure decentralized KP-ABE scheme, where no CA exists and there is no cooperation between any AAs. To become an AA, a participant needs to create and publish its public parameters. All the user's private keys will be linked with his unique global identifier (GID). The proposed scheme supports any monotonic access structure which can be expressed by a linear secret sharing scheme (LSSS). We prove the full security of our scheme in the standard model. Our scheme is also secure against at most F-1 AAs corruption, where F is the number of AAs in the system. The efficiency of our scheme is almost as well as that of the underlying fully secure single-authority KP-ABE system.