Research On Attribute-based Encryption Scheme Supporting Traitor Tracing

At present,people are increasingly inclined to acquire knowledge and store information through the Internet with the widespread popularity of mobile socialization and the rapid development of cloud computing,and the data in the Internet is exploding.At the same time,information security problems are becoming more and more serious,the leakage of information such as individuals and enterprises has frequently exploded.In view of the above factors,data security in the big data environment has become a hot spot for researchers.As an important branch of cryptography,the attribute-based encryption mechanism realizes the control of user access to data by matching the relationship between the structure and the attribute set,and it can solves the problem of "one-to-many" secret data sharing effectively in the cloud.There are extensive research and applications in the fields of computing,big data,and privacy protection.However,in the actual application of the attribute-based encryption mechanism,there are also some defects.For example,some users unintentionally or intentionally disclose the private key,which poses a threat to data security;and when different users have the same attribute,their access rights will be the same.At this time,there will be a problem that the system will not distinguish the same attribute's different authority for different users.Therefore,this paper mainly studies the attribute-based encryption scheme in two aspects,they respectively are traitor's accountability and attribute weight.The specific research results are as follows:(1)Aiming at the problem that traitors leak private keys to obtain illegal benefits in practical applications,we propose a cipher-text policy attribute-based encryption scheme that supports traitor tracking.This scheme combines the Boneh-Boyen signature algorithm with the private key generation algorithm to achieve traitor tracking by embedding the user identity.We use a tree-shaped access structure so that our scheme can be greater flexibility,and when the traitor's private key can satisfy the plausibility test,the traitor identity can be calculated.It is also proved that our scheme satisfies chosen plaintext attack security under the DBDH assumption.The performance analysis shows that the size of our scheme's cipher-text and private key is shorter,which reduces the computational overhead and communication overhead.(2)Considering the different degrees of user attributes importance during the traitor tracing in practical applications,we propose a weight attribute-based encryption scheme supporting traitor tracking.Our scheme embeds user's identity information into user's private key and tracks malicious users who have leaked key information from the system.We use the attribute weight,and the attribute set is transformed into attribute weight segmentation set by attribute set segmentation algorithm,and access control is realized by linear secret sharing,which makes it closer to the actual environment.It is also proved that under the assumption of q-DBDH,our scheme satisfies the choice of plaintext attack security in the standard model.Compared with other schemes,our scheme has a significant improvement in communication and computational cost.