Research On Technology Of Attribute-based Encryption For VANETs

In recent years,the data security of the vehicular ad-hoc network(VANET)has attracted attention from researchers.Due to the high dynamics of vehicles and the limitations of calculation,storage,and transmission capabilities,traditional group encryption costs a lot on key management,and it is difficult to maintain groups.Therefore,constructing an encryption system suitable for VANETs has become a hot topic.In adition,AttributeBased Encryption(ABE)provides a solution for “one-to-many” transmission,and it can be applied to the secure transmission in VANETs.However,the existing ABE schemes for VANETs still have some problems,such as low efficiency and imperfect functions.This paper researches the Ciphertext Policy Attribute-Based Encryption(CP-ABE)technology for VANETs.Firstly,we analyzes the demand for secure transmission of VANETs and construct a traceable and revocable ABE scheme TR-CP-ABE,which provides a fine-grained access control mechanism for VANETs.The data sender uses the linear secret sharing scheme to define access structure.Only the users whose attributes satisfie the access structure can decrypt.In ABE system,the behavior of revealing key is difficult to be caught.Therefore,TR-CP-ABE implements the tracking mechanism by maintaining an identity list,and provides a revocation mechanism when the system changes and revokes users.TR-CP-ABE provides a flexible and safe solution for data transmission in VANETs.Secondly,we proposes an efficient and traceable ABE scheme ET-ABE1.The decryption key is constant-size and is nonlinear with the number of users' attributes.In addition,ET-ABE1 can trace malicious users with low cost.The burden of transmission and storage keys is greatly reduced without sacrificing computing efficiency.And we prove the CCA security of the scheme under the selective security model.Finally,tracing malicious users at a lower cost on the basis of providing short keys is researched.We proposes an enhanced traceable ABE scheme ET-ABE2.The Shamir(?t,?n)threshold scheme is used to replace the original user identity list so that the cost of tracing malicious users does not increase linearly with the number of users.We compare the efficiency with others,and carry out experiments to show the feasibility for VANETs.