Research On Efficient Attribute-based Signcryption Scheme Supporting Outsourcing

Attribute-based cryptosystem is one of the hotspots of current cryptography research.As a new public key cryptosystem,this mechanism can combine attributes with keys or ciphertext to provide a highly flexible access control strategy.The application of attribute-based cryptosystem can be divided into three types,attribute-based encryption,attribute-based signature,and attribute-based signature.The attribute-based signcryption combines the function of attribute-based encryption with the function of attribute-based signature,which has good research value and application prospects.However,the existing attribute-based signcryption scheme still has many problems to be solved.For example,the public-private key and the ciphertext length will increase as the number of attributes increases,and the calculation overhead will increase as the number of users increases.Due to the characteristics of the attribute-based signcryption technology,the signcryption and decryption key calculation process includes a large number of bilinear pair operations and modular exponential operations on the group.This paper introduces the security outsourcing computing technology to improve the existing attribute-based signcryption algorithm.In order to realize the combination of attribute-based signcryption algorithm and security outsourcing computing technology,the paper first studies the solution of using security outsourcing computing technology to improve the operating efficiency of traditional public key encryption system,and designs an outsourcing decryption scheme for El-Gamal encryption system.The decrypter sends the blinded key to the outsourced decryption server,and the outsourced server converts the signed ciphertext,undertakes most of the computing work,and then sends the converted information to the decrypter so that it can be less after the calculation,the information is unlocked.Then according to the idea and technical points of the program,an attribute-based signcryption system that supports outsourcing and traceability is proposed.The main research contents are as follows:1)The paper proposes an outsourced decryption solution for the El-Gamal encryption system,which uses the cloud platform to provide users with the computing power of high-performance hardware.Based on the scheme,we designed a cloud cryptosystem to verify the scheme.For the proposed system,we performed relevant experimental analysis and simulated the operational efficiency of its implementation of the El-Gamal decryption algorithm.2)According to the proposed security outsourcing El-Gamal encryption scheme decryption scheme,and using the key blinding idea and related technology,this paper proposes an efficient and traceable efficient traceability attribute-based signcryption scheme.In addition,this paper conducts a security analysis on the proposed efficient and traceable attribute-based signcryption scheme for outsourcing,and proves the security of the scheme.At the same time,the paper analyzes the performance of the scheme and the experimental simulation and compares it with the performance of other property-based signcryption schemes.