A SURVEY ON CRYPTOGRAPHIC CLOUD STORAGE WITH KEY AGGREGATE SEARCHABLE ENCRYPTION

Cloud is a new way to store large amount of data. In cloud computing, data owners host their data on cloud servers and users can access the data from cloud servers. By data outsourcing, users can be relieved from the burden of local data storage and maintenance. Cloud storage has emerged as a promising solution for providing ubiquitous, convenient, and on-demand accesses to large amounts of data shared over the Internet.Considering the practical problem of privacy preserving data sharing system based on public cloud storage which requires a data owner to distribute a large number of keys to users to enable them to access his/her documents, we for the first time propose the concept of key-aggregate searchable encryption (KASE) and construct a concrete KASE scheme. Both analysis and evaluation results confirm that our work can provide an effective solution to building practical data sharing system based on public cloud storage

Sharing of Data Using Key Aggregation and Searchable Encryption

Sharing data with different users is an important functionality of the cloud. However, while enjoying the convenience provided by the cloud storage, user’s main concern is regarding the data leakage present in cloud. A promising approach to prevent this is encryption of data before uploading onto cloud. The desire to selectively and securely share documents with any group of users demands different documents to have different encryption keys. This necessitates the distribution of a large number of keys to users for both encryption and search, those users will have to securely store these keys, and submit an equally large number of keyword trapdoors to the cloud in order to perform search. In this paper, we resolve this problem by extending the concept of Key Aggregate Searchable Encryption (KASE) scheme which employs a single aggregate key and a single trapdoor. Here, the data owner only needs to distribute a single key to a user for sharing a large number of documents, and the user only needs to submit a single trapdoor to the cloud for querying the documents. Also, we provide a functionality of selection of keyword based on their rank by the Data owner in such a way that the selected keywords describe the file. Thus, this scheme makes the management of the keys efficient and also makes the sharing of documents over the cloud more secure

Optimal and Efficient Searchable Encryption with Single Trapdoor for Multi-Owner Data Sharing in Federated Cloud Computing

Cloud computing, an Internet based computing model, has changed the way of data owners store and manage data. In such environment, data sharing is very important with more efficient data access control. Issuing an aggregate key to users on data enables and authorizes them to search for data of select encrypted files using trapdoor or encrypted keyword. The existing schemes defined for this purpose do have certain limitations. For instance, Cui et al. scheme is elegant but lacks in flexibility in access control in presence of multiple data owners sharing data to users. Its single trapdoor approach needs transformation into individual trapdoors to access data of specific data owner. Moreover, the existing schemes including that of Cui et al. does not support federated cloud.  In this paper we proposed an efficient key aggregate searchable encryption scheme which enables multiple featuressuch as support for truly single aggregate key to access data of many data owners, federated cloud support,query privacy, controlled search process and security against cross-pairing attack. It has algorithms for setup, keygen, encrypt, extract, aggregate, trapdoor, test and federator. In multi-user setting it is designed to serve data owners and users with secure data sharing through key aggregate searchable encryption The proposed scheme supports federated cloud. Experimental results revealed that the proposed scheme is provably secure withrelatively less computational overhead and time complexity when compared with the state of the art