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Research And Implementation Of Time-Sensitive Multi-Authority Attribute-Based Encryption

Posted on:2023-03-26Degree:MasterType:Thesis
Country:ChinaCandidate:J Y GaoFull Text:PDF
GTID:2558306914983549Subject:Cyberspace security
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With the trend of data sharing among multiple parties in cloud storage,data security and privacy protection are particularly important.Data sharing scenarios are also becoming more and more complex,and time-related access control scenarios,i.e.,film-releasing and electronic bidding,have increased.Therefore,it is required that flexible time-sensitive schemes in access control should be studied.There are several technical challenges in designing such schemes.On the one hand,the time-dependent access control algorithm needs to be combined with CPABE to improve data confidentiality.On the other hand,the scheme should be designed to be anti-collusion.The existing time-sensitive access control schemes are not suitable to be applied directly in cloud storage environments,because these schemes may have security risk of falsifying time attributes.They are not efficient enough,and they do not support running in a distributed computing environment.For the sake of solving the problems,this paper proposes an efficient timesensitive attribute-based encryption algorithm called TSM.TSM draws on the construction of TRE,using LSSS as the access structure,and divides the user’s private key into two parts:a time-related key and an attribute-related key.TSM consists of 4 stages,with 8 sub-algorithms,and requires data interaction between 6 entities.When using TSM,the data owner pre-sets a valid time of a certain file,and then uploads the encrypted file to the cloud storage platform.The data visitor cannot decrypt the ciphertext until the valid time arrives.TSM has been proved to achieve indistinguishability under chosen-plaintext attack(IND-CPA in short)if the q-BDHE assumption holds.Comparative analysis shows that TSM has better performance under the premise of ensuring security.When sharing data to multiple parties in cloud storage,it is possible that there are more than one file or directory to be shared,and different directories or files require different access policies.Separating access policies for each directory incurs the overhead of key generation and key management that increases exponentially with the number of directories.In order to reduce the overhead of key generation and management,this paper optimizes TSM,and designs a timesensitive file-hieratical multi-organization attribute encryption scheme based on the tree structure,which can encrypt and decrypt directories at all director-levels.Finally,in order to easily apply TSM into specific scenarios,this paper constructs a system which combines the symmetric encryption algorithm and TSM.The combination can help greatly reduce the computational consumption while maintaining the flexibility and security of ABE.Experiments show that the performance of the proposed scheme is better than other attribute encryption schemes.
Keywords/Search Tags:multi-authority attribute-based encryption, multi-party data sharing, time-sensitive, access control
PDF Full Text Request
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