Secure Data Group Sharing and Conditional Dissemination with Multi-Owner in Cloud Computing

Abstract : With the rapid development of cloud services, huge volume of data is shared via cloud computing. Although cryptographic techniques have been utilized to provide data confidentiality in cloud computing, current mechanisms cannot enforce privacy concerns over cipher text associated with multiple owners, which makes co-owners unable to appropriately control whether data disseminators can actually disseminate their data. In this paper, we propose a secure data group sharing and conditional dissemination scheme with multi-owner in cloud computing, in which data owner can share private data with a group of users via the cloud in a secure way, and data disseminator can disseminate the data to a new group of users if the attributes satisfy the access policies in the cipher text. We further present a multiparty access control mechanism over the disseminated cipher text, in which the data co-owners can append new access policies to the cipher text due to their privacy preferences. Moreover, three policy aggregation strategies, including full permit, owner priority and majority permit, are provided to solve the privacy conflicts problem caused by different access policies. The security analysis and experimental results show our scheme is practical and efficient for secure data sharing with multi-owner in cloud computing.

 EXISTING SYSTEM :

 Identity-based systems allow any party to create a public key from a known identity value such as an ASCII string (e.g. email id). Figure shows an Identity based Encryption scenario. A trusted third party called as Private Key Generator, which generates the corresponding private keys. To operate, the Private Key Generator first distributes a master public key, and retains the equivalent master private key. Given the master public key, any party can compute a public key related to the identity by combining the master public key with the identity value. To achieve a corresponding private key, the party authorized to use the identity ID contacts Private Key Generator, which uses the master private key to create the private key for identity ID. As a result, parties may encrypt messages without prior distribution of keys between individual participants.

 DISADVANTAGE :

 Problem Statement Secure multi-owner data sharing scheme, it implies that any user in the group can securely share data with others by the entrusted cloud. Support dynamic groups efficiently. Specifically, new granted users can directly decrypt data files uploaded before their participation without contacting with data owners.

 PROPOSED SYSTEM :

 In our plan, data co-owners can recharge the cipher texts by annexing their entrance approaches as the Spread conditions. As depicted in, we give following procedures to satisfy the approval prerequisites from multiowner, as appeared in. Three policy aggregation strategies with multi-owner. 1) Full license: All owners (counting data owner and data co-owners) have a similar right to choose the Scattering states of data. The data disseminator ought to fulfill all the entrance arrangements characterized by these owners. 2) Owner need: The data owner's choice has high need, however he labels the co-owners. The data disseminator can disperse the data just when he fulfills the entrance arrangement of data owner or all the entrance strategies of data crowners. 3) Majority grant: The data owner right off the bat picks edge esteem, and the data can be spread if and just if the entirety of access strategies fulfilled by disseminator's properties is more noteworthy than or equivalent to this fixed limit.

 ADVANTAGE :

 ? Any user in the group can store and share data files with others by the cloud. ? The encryption complexity and size of cipher texts ar independent with the number of revoked users in the system. ? User revocation can be achieved without updating the private keys of the remaining users. ? It provides the services as a low maintenance cost and high quality services.