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Practical Private Information Retrieval Supporting Keyword Search In The Cloud

Posted on:2016-01-25Degree:MasterType:Thesis
Country:ChinaCandidate:M K YuFull Text:PDF
GTID:2298330470957753Subject:Information and Communication Engineering
Abstract/Summary:PDF Full Text Request
In cloud computing, numerous queries sent by users are transferred in the whole world, making queries more vulnerable to stolen and attacks. Protecting users’ privacy and preventing cloud service providers from maliciously leaking or mining users’ privacy are a huge challenge. Currently, conventional methods, including encryption, searching over encrypted data, access control and anonymous credential, can not protect the leakage of access patterns. Traffic analysis techniques can reveal sensitive information against privacy. For example, access history could disclose users’ retrieval habits or identities; accesses to the same data may indicate the relationship between multiple users. Fortunately, Private Information Retrieval (PIR) is a technique allowing users retrieving without the server learning which data items have been retrieved. Therefore, PIR can prevent the leakage of access patterns.In this paper, we review the related work and study the PIR supporting keyword search. The main contents and contributions in this paper are as follows:1. A PIR protocol supporting keyword search (ksPIR) is proposed. Most existing PIR solutions only allow the retrieval by the address which is not available to users in cloud computing environment. Therefore, PIR supporting keyword search (ksPIR) is proposed. The ksPIR can not only protect the contents of requests but also protect the identities of data items which have been retrieved.2. A practical Pay-Incentive ksPIR protocol is proposed. The ksPIR protects users’ access patterns by transferring too many data items and executing too expensive operations. It is not practical and flexible due to its huge communication and computation overhead. Therefore, we proposed the Pay-Incentive ksPIR to achieve the tradeoff between the cost of retrieval and the degree of privacy. We achieve minimal communication and computation overhead by introducing users’ specifications about the privacy and budget.3. A model of measure standard for costs of PIR is proposed. At present, the PIR studies have not extended to the real cloud environment. There is not a unified measure standard for costs of PIR. Therefore, we combine charge standards of cloud service providers and analyses of academic circles to propose a measure standard for costs of PIR using unified units. On this basis, we use this model to compare costs of several typical ksPIR protocols to provide reference for different users.
Keywords/Search Tags:Cloud Security, PIR, Keyword Search, Access Pattern, Practical
PDF Full Text Request
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