Research On The Verifiable Of Attribute-Based Encryption With Outsourcing

Attribute-based encryption achieves user fine-grained access control.However,it is not suitable for real-world scenarios since large decryption computation and ciphertext integrity cannot be verified.The verifiable of attdcmribute-based encryption with outsourcing schemes can eliminate the decryption overhead for user,achieve message integrity and ensure system security.Therefore,it become a hot research topic to build a secure and efficient verifiable of attribute-based encryption with outsourcing schemes.This thesis study deeply the verifiable of attribute-based encryption with outsourcing schemes focused on different functions.The main work is summarized as follows.(1)For the problem of attribute revocation in the verifiable of attribute-based encryption with outsourcing schemes,this thesis proposes a secure verifiable attribute-based encryption with outsourcing scheme in the standard model,which supports attribute revocation.The scheme uses linear secret sharing and KUNode algorithms to achieve fine-grained access control and attribute revocation respectively,meanwhile,which satisfies the verifiable of ciphertext.Security analysis shows that the proposed scheme based on the q-decisional bilinear Diffie-Hellman exponent assumption(q-DBDHE)satisfies the indistinguishable under adaptive choice plaintext attack.Compared with the exist schemes,the proposed scheme has the function of attribute revocation and meets the needs of ciphertext integrity verification.The computational complexity of the proposed scheme is reduced and the system efficiency is higher in the phases of key,encryption and decryption.(2)Aiming at the problem that the verifiable of attribute-based encryption with outsourcing schemes can't limit the times of outsourcing decryption,this thesis proposes a secure verifiable of attribute-based encryption with outsourcing scheme which can support N times of decryption in the standard model.The scheme implements outsourcing encryption and decryption,uses key derivation function and commitment scheme achieves verifiable,and uses verifiable random function achieves N decryption restrictions.Security analysis shows that,base on the assumptions of q-decisional bilinear Diffie-Hellman inverse problem and q-decisional bilinear Diffie-Hellman exponent problem assumption,the proposed scheme is proved that it can satisfy the indistinguishable under adaptive choice plaintext attack.Compared with the verifiable attribute-based encryption with outsourcing schemes,the proposed scheme satisfies the functions of outsourcing encryption,N times outsourcing decryption and verifies message integrity.In addition,It has higher computational efficiency,and can be more suitable for real-world scenarios.