Efficient and secure ranked multi-keyword search on encrypted cloud data

Information search and document retrieval from a remote database (e.g. cloud server) requires submitting the search terms to the database holder. However, the search terms may contain sensitive information that must be kept secret from the database holder. Moreover, the privacy concerns apply to the relevant documents retrieved by the user in the later stage since they may also contain sensitive data and reveal information about sensitive search terms. A related protocol, Private Information Retrieval (PIR), provides useful cryptographic tools to hide the queried search terms and the data retrieved from the database while returning most relevant documents to the user. In this paper, we propose a practical privacy-preserving ranked keyword search scheme based on PIR that allows multi-keyword queries with ranking capability. The proposed scheme increases the security of the keyword search scheme while still satisfying efficient computation and communication requirements. To the best of our knowledge the majority of previous works are not efficient for assumed scenario where documents are large files. Our scheme outperforms the most efficient proposals in literature in terms of time complexity by several orders of magnitude

Privacy-preserving targeted advertising scheme for IPTV using the cloud

In this paper, we present a privacy-preserving scheme for targeted advertising via the Internet Protocol TV (IPTV). The scheme uses a communication model involving a collection of viewers/subscribers, a content provider (IPTV), an advertiser, and a cloud server. To provide high quality directed advertising service, the advertiser can utilize not only demographic information of subscribers, but also their watching habits. The latter includes watching history, preferences for IPTV content and watching rate, which are published on the cloud server periodically (e.g. weekly) along with anonymized demographics. Since the published data may leak sensitive information about subscribers, it is safeguarded using cryptographic techniques in addition to the anonymization of demographics. The techniques used by the advertiser, which can be manifested in its queries to the cloud, are considered (trade) secrets and therefore are protected as well. The cloud is oblivious to the published data, the queries of the advertiser as well as its own responses to these queries. Only a legitimate advertiser, endorsed with a so-called {\em trapdoor} by the IPTV, can query the cloud and utilize the query results. The performance of the proposed scheme is evaluated with experiments, which show that the scheme is suitable for practical usage

Performance Study of Cryptography based Dynamic Multi-Keyword Searchable Security Algorithm in Cloud Using CRSA /B+ Tree

Today, Cloud computing is a buzz word in IT industry. Cloud, a shared pool of computing resources, allows access to needed resources on demand through internet and web applications. Since data is outsourced to third party, user needs to maintain the accountability of their data in cloud. Hence preserving the confidentiality and securing the sensitive data in cloud is a major concern. Many cryptographic techniques have been proposed by researchers to assure the confidentiality of the user2019;s data in cloud. But, the challenging task is to provide the secure search over this preserved data which has been encrypted so as to retrieve the effective data. Hence, we are proposing a system to have a secure search over the encrypted data on the cloud which preserves its confidentiality. In our system, a noble approach has been made using the Commutative-RSA algorithm, a cryptographic technique where the dual encryption takes place thus reducing the overall computation overhead. The search operation over the encrypted data is based on the tree search algorithm which supports multi-keyword search. Based on the relevance score, the more appropriate data is retrieved on the search operation. Using this approach, the information is not leaked when the encrypted data is searched by users and also the queries are handled in an efficient way. Finally, we demonstrate the effectiveness and efficiency of the proposed schemes through extensive experimental evaluation