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Research On Novel Attribute Based Encryption Algorithms For Cloud Data

Posted on:2020-11-27Degree:MasterType:Thesis
Country:ChinaCandidate:S Y ZhaoFull Text:PDF
GTID:2428330620456216Subject:Electronic and communication engineering
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The development of network technology improves the speed of information transmission and the storage space,which promotes the development of cloud computing and big data.The cloud computing and big data provides convenience for users to share their data and saves the cost of local data storage and management.For example,each user can use Baidu SkyDrive and other cloud storage applications to provide private space and upload videos,text files or other resources to share with other people according to their personal requirements,thus plays an important role in daily life.To ensure the security of cloud storage data,ABE has become one of the most commonly used encryption schemes.It can fine-grained control users' data access right,which is very suitable for complex and changeable data sharing environment in reality.However,some problems that have not been completely solved by ABE,including key escrow problem,collusion attack,secure secret key distribution and secure attribute revocation,may cause security issues.Besides,the security of existing encryption schemes are guaranteed by large prime problems and discrete logarithm problems,which have been proved cannot resist quantum attack with the development of quantum computer technology.Therefore,lattice based encryption has been proposed.These encryption scheme are on the basement of lattice hardness problems,which can ensure their security.The details are as follows:Firstly,in this thesis,we propose a secure data sharing scheme with two level revocation in the cloud computing(SDSS-TLR).In this scheme,we can embed secret values related to the users' identity and keep these secret values can not be obtained by entities other than the key distribution center,thus can resist collusion attacks between users and users,users and cloud servers.In this scheme,we can generate secret keys through the cooperation between two different entities,in which each entity owns some components of master keys,then sends the secret key components to the users separately,thus solve the key escrow problem.In this scheme,we can ensure attribute distribution and revocation with high security and efficiency,in which both the forward and backward security can be ensured.In this scheme,we ensures secure secret key distribution under the condition that all information is transmitted through public channels only except the user registration period.Besides,in the proposed SDSS-TLR,we can make two different kinds of revocations.One is the normal attribute-level revocation and the other is an user-level revocation that can make an users revocation list to revoke some users directly.Secondly,in this thesis,since traditional ABE schemes can no longer resist quantum attacks,we proposes a revocable lattice Attribute-based Encryption scheme based on R-LWEproblem in cloud computing(RL-ABE).In this scheme,we set some trapdoor functions according to lattice hardness problem to generate public/secret key pairs of attributes and secret values,thus generates ciphertext and secret keys based on lattice hardness problems to ensure the quantum-resistance ability.Later,we make formal proof to ensure the security against quantum attack.Besides,in this scheme,we can resist security attacks,including collusion attacks among different users and users and outside attackers.In this scheme,we can achieve fine-grained access control while the traditional lattice based encryption schemes cannot by combining the ABE scheme with the lattice based encryption scheme,thus can flexibly control users' data sharing ability.In addition,the existing lattice based Attribute-based Encryption schemes have the drawback of not being able to complete attribute revocation,in our RL-ABE scheme,we can realize effective and secure attribute revocation to the users.In this thesis,we can renew users' attributes to dynamic control users' access rights by distributing update components to replace attribute related values in the scheme.Finally,this thesis proposes a lattice based ABE scheme,which is based on both NTRU and R-LWE problem.Since most of the existing lattice based ABE schemes in cloud environment are based on the R-LWE problem.The resulting scheme can ensure security and high efficiency.However,comparing to the other traditional ABE schemes and lattice based encryption schemes,although the combining schemes can guarantee higher security,flexibility and fine-grained control capabilities,the storage load and computation load are increased due to the need of using a set of lattice to replace a single number to represent attributes and the need of generating more sets of lattice for a larger number of attributes.Therefore,in this scheme,we realizes encryption and decryption phase through NTRU problem to improve the efficiency of the algorithm.At the same time,it generates key by setting trapdoor functions according to the R-LWE problem,which guarantees the security of the algorithm against quantum attack,collusion attack and other attacks.In addition,we improve the problem of probabilistic decryption failure of the encryption schemes based on NTRU problem.
Keywords/Search Tags:cloud storage, attribute-based encryption, lattice based encryption, revocation, key escrow problem, R-LWE problem, NTRU algorithm
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