Multikeyword Rank Search Scheme for Unindexed Encrypted Cloud Data

Vaishali B Bambode
2020 International Journal for Research in Applied Science and Engineering Technology  
Due to the increasing popularity of cloud computing, more and more data owners are motivated to outsource their data to cloud servers for great convenience and reduced cost in data management. However, sensitive data should be encrypted before outsourcing for privacy requirements, which no longer support data utilization like keyword-based document retrieval. In this project, we present a secure multi keyword ranked search scheme over encrypted cloud data, which simultaneously supports dynamic
more » ... pdate operations insertion and updating of documents. Specifically, We construct a special tree-based index structure and propose a "Greedy Depth-first Search" algorithm to provide efficient multi-keyword ranked search. The secure kNN algorithm is utilized to encrypt the index and query vectors, and meanwhile ensure accurate relevance score i.e keyword weitage calculation between encrypted index and query vectors. In order to calculate the TF value of the search keyword we use a pattern matching algorithm which indicates the occurrence of that particular keyword in a file. Due to the use of our special tree-based index structure, the proposed scheme can achieve sub-linear search time and deal with the insertion and updating of documents flexibly. Index Terms: Cloud Computing, Multi keyword rank search scheme ,TF ,KNN algorithm, Greedy DFS algorithm I. INTRODUCTION Cloud computing has been emerged as a new model of IT infrastructure, which helps to organize huge resource of computing, storage and applications, and enable users to enjoy convenient and on demand network access to a shared pool of computing resources with great efficiency and minimal economic overhead . Because of these appealing features of cloud computing ,both individuals and enterprises are motivated to outsource their data to the cloud. Despite of various advantages of cloud computing services ,outsourcing sensitive information like e-mails, personal health records ,government data or documents to remote servers have always privacy concerns. The cloud service providers (CSPs) that keep the data for users may access users sensitive information without authorization. A general approach to protect the data confidentiality is to encrypt the data before outsourcing. Multi-keyword ranked search over encrypted cloud data (MRSE) was introduced in 2014 by N. Cao et al. The main idea of this scheme was to allow users on search request and return documents with semantic multiple keywords . In order to secure and get the most relevant results retrieval, MRSE was adapted from secure k-nearest neighbor (kNN) technique to select the k nearest database records between database record and query vector. Secure inner product computation was adopted in order to set strict privacy requirement to ensure secrecy of cloud communication . Recently, some dynamic schemes have been proposed to support inserting and updating operations on document collection. It is highly possible that the data owners need to update their data on the cloud server. But few of the dynamic schemes support efficient multi-keyword ranked search. This project proposes a secure tree-based search scheme over the encrypted cloud data, which supports multi-keyword ranked search and dynamic operation on the document collection. In order to obtain high search efficiency, we construct a tree-based index Multikeyword Rank Search Scheme For Unindexed Encrypted Cloud Data structure and propose a -Greedy Depth-first Search (GDFS)‖ algorithm based on this index tree. Due to the special structure of tree-based index, the proposed search scheme can flexibly achieve sub-linear search time and deal with the deletion and insertion of documents. The secure KNN algorithm is utilize to encrypt the index and query vectors, and meanwhile ensure accurate relevance score calculation between encrypted index and query vectors. . In order to calculate the TF value of the search keyword we use a pattern matching algorithm like Naïve algorithm which indicates the occurrence of that particular keyword. In existing system, The techniques of data updating are utilizes effectively but there is big problem in working with sharing keys and decrypted data with other users which may disturb the security as well in this a unencrypted index key is used for ranking which may break security as well. So that we proposed a mechanism in which the encrypted index term key will get generated and perform the evaluation for the multi keyword searching in all encrypted cloud storage.
doi:10.22214/ijraset.2020.30517 fatcat:ltapmkajs5bm7ni2nmzyy6cqc4