The Research Of Efficient Aggregate Signcryption In Internet Of Vehicles

In Internet of Vehicles(Io V)system,the massive privacy data generated by vehicles is transmitted in the open channel,and Cloud Server receives the data through wireless technology and makes use of it,so as to better serve users based on their data.Therefore,ensuring information security and improving transmission efficiency are two major difficulties in Io V.Aggregate signcryption can solve these two problems.It encrypts and signs data at the same time,and then aggregates several signcryptions into a ciphertext for transmission.During the unaggregate process,the receiver compresses the verification and unsigncryption operations of multiple signcryptions into one operation.If the verification is passed,all ciphertexts are accepted.However,the existing aggregate signcryption schemes are imperfect,for example,no fault-tolerant or fault-tolerant defects,no unbounded aggregation and poor flexibility in application,don’t support verify whether two ciphertexts contain the same plaintexts resulting in low application efficiency,certificate and key management difficulties in some schemes.This thesis carries out research aim at solving these problems.Firstly,this thesis proposes a heterogeneous fault-tolerant aggregate signcryption scheme with equality test for heterogeneous cryptography environment.The scheme adds ciphertext equality test function based on unbounded fault-tolerant aggregate signcryption,which ensures fault-tolerance,flexibility,and application efficiency of the scheme.The scheme supports data communication from public key infrastructure to identity-based cryptosystem.The scheme uses techniques based on cover-free families and nested families to achieve unbounded fault-tolerant aggregation,resulting in an efficient,full-featured fault-tolerant scheme,and its ciphertext equality test achieves efficient access control of data.Secondly,this thesis proposes a certificateless and faulttolerant aggregate signcryption for certificateless cryptography environment.The scheme directly avoids the two major issues of certificate management and key escrow by using certificateless cryptography,and uses elliptic curve to construct scheme algorithms,which reduces administrative and computational overhead.In addition,the scheme provides pseudonyms for vehicles,and vehicles send data on condition of anonymity,ensuring the privacy of users.This thesis has carried out strict security proof and experimental comparison for both proposed schemes,and concluded that compared to existing schemes,while ensuring security,the two proposed schemes achieve a more complete function of unbounded faulttolerant aggregation with less communication and computing overhead and higher efficiency in identifying invalid signcryptions,and are suitable for complex Io V environments.