Research On Attribute-based Signcryption Scheme

Attribute-based signcryption mechanism can complete attribute-based encryption and signature in one step.This mechanism not only provides data confidentiality and authentication,but also achieves fine-grained access control and data sharing.Therefore,the research of attribute-based signcryption mechanism is of great significance in practical application and has become a hot topic in cryptography.In this paper,the attribute-based signcryption mechanism is studied in depth,including:(1)Aiming at the leakage of personal sensitive information of data owners in electronic health record system,a new attribute-based signcryption scheme supporting privacy-preserving is proposed based on bilinear pairings and combing attribute-based signcryption mechanism with Cuckoo filter technology.Under the standard model,based on the decisional bilinear Diffie-Hellman exponent assumption and computational Diffie-Hellman exponent assumption,it is proved that the scheme satisfies the indistinguishability under adaptive chosen ciphertext attack and the unforgeability under adaptive chosen message attack,respectively.Compared with the existing schemes,the proposed scheme not only achieves fine-grained access control of data and protection of user's privacy information,but also has high communication overhead and computational cost,and is more suitable for electronic health record system.(2)Aiming at the problem that malicious users leak secret keys and abuse keys in cloud storage system,an attribute-based signcryption scheme supporting user tracing and revocation is proposed based on bilinear pairings and combing attribute-based signcryption mechanism with binary Key Encryption Key(KEK)tree.Under the standard model,based on the decisional bilinear Diffie-Hellman exponent assumption,computational Diffie-Hellman exponent assumption and l-strong Diffie-Hellman exponent assumption,it is proved that the scheme satisfies the indistinguishability under the adaptive chosen ciphertext attack,the unforgeability under the adaptive chosen message attack and the complete traceability,respectively.At the same time,the scheme is revocable.Compared with the existing schemes,the proposed scheme can efficiently trace user and revoke user's attribute,and resist collusion attacks of malicious users.It is more suitable for the practical application of cloud storage system.