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Researches On Design And Security Of Multi-user And Multi-function Searchable Encryption In Cloud Computing

Posted on:2020-02-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:P M XuFull Text:PDF
GTID:1368330620958554Subject:Computer Science and Technology
Abstract/Summary:PDF Full Text Request
With the rapid development of cloud storage services,in order to reduce the consumption of local computing and storage resources,more and more users and enterprises choose to purchase cloud storage services and store private data in cloud servers.However,cloud service providers are not completely trustworthy.The data storage in plaintext form must pose a serious threat to data privacy,such as the business data,private diaries,private photos,personal medical data,etc,which may be maliciously stolen by cloud service providers under the influence of interests,or be stolen by malicious attackers through centralized network attacks.In order to protect data privacy,encrypting data and storing it in ciphertext form,is the most recognized solution by scholars.However,encrypted data limits the ability of service providers to process data,such as the keyword search,which is the most commonly used in daily life.Therefore,how to efficiently search over ciphertext and not reveal user privacy data has become an urgent and challenging problem in the wide application of cloud computing.This paper mainly studies the functions,efficiency and security problems existing in the three searchable encryption architectures(including M/S architecture,S/M architecture and M/M architecture),which are applicable to multi-user scenarios.The main contributions are described as follows:(1)Focusing on the problems about the low efficiency and single search function of the M/S searchable encryption architecture,which is applicable to encrypted email,we propose an efficient M/S searchable encryption scheme that supports multi-keyword search and boolean query,named PMSEHS.With the help of hidden star structure and anti-collision element set,the search efficiency is effectively improved,and the complexity is reduced from O(n)of most existing schemes to O(r),where n is the total number of data,r is the number of relevant data.In real-world applications,r satisfies the feature of being much smaller than n.And the experimental results fully demonstrate the search efficiency advantage of our scheme.In addition,our PMSEHS scheme can be proven to satisfy encrypted indexes indistinguishability.(2)Focusing on the problems about the low efficiency,the inability to resist off-line keyword guessing attacks and the requirement of trusted intermediate servers,of the S/M searchable encryption architecture,which is applicable to cloud enterprise data authorization,we propose an efficient S/M searchable encryption scheme,which do not require trusted intermediate servers and can resist off-line keyword guessing attacks,named DuMSE.With the help of hidden star structure,the search efficiency is also effectively improved,and the experimental results also fully demonstrate the search efficiency advantage of our scheme.In terms of security,our DuMSE scheme can be proved to satisfy encrypted indexes indistinguishability and search trapdoor indistinguishability.And a DuMSE scheme,which satisfies search trapdoor indistinguishability,can resist off-line keyword guessing attacks.In addition,we also propose a dynamic extension of the DuMSE scheme.Although the storage consumption is increased compared to the DuMSE scheme,the low search time consumption is maintained.(3)Focusing on the problems about the low efficiency,the requirement of trusted intermediate servers and the inability to prevent the leakage of search pattern and access pattern,of the M/M searchable encryption architecture,which is applicable to cloud group data sharing,we propose an efficient M/M searchable encryption scheme,which do not require trusted intermediate servers,no search pattern and access pattern disclosure,support revocation,satisfy the provable security,forward security,and backward security,named SGDS.With the help of the basic idea of path ORAM technology,the SGDS scheme can prevent the leakage of search pattern and access pattern.We also formally prove that the SGDS scheme satisfies the ciphertext indistinguishability.In terms of efficiency,with the help of the inverted index,the search complexity is reduced from O(n)to O(r),where n is the total number of data,r is the number of relevant data.And the experimental results fully demonstrate the search efficiency advantage of our scheme.
Keywords/Search Tags:Searchable encryption, privacy protection, encrypted email, multi-keyword search, boolean query, group data sharing
PDF Full Text Request
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