Research On Key Technologies Of Identity-based Encryption From Lattices

With the rapid development of quantum computing,internet of things and cloud computing technology,the secure transmission of information is increasingly essential.Identity-based encryption(IBE)is one of the principal technical means to ensure information security.In addition to resisting quantum attacks,lattice-based encryption schemes have the advantages of high concurrency,small operands and high efficiency,which have become a hot research topic in the post-quantum era of information security.Because the traditional IBE scheme cannot resist the quantum attack and the computational overhead of the private key generation center(PKG)is large,this thesis proposes two lattice-based schemes by studying and researching the current IBE schemes.Aiming at the problem that traditional hierarchical revocable IBE scheme cannot resist quantum attacks,this thesis proposes a hierarchical revocable IBE scheme from lattice for the first time.This scheme is based on the problem of learning with error on lattice and combines the binary tree node selection algorithm with the hierarchical encryption scheme proposed by Agrawal et al.The adaptive security of the new scheme is proved under the standard model.The computational complexity of lattice-based difficult problems enhances the security of the scheme,which ensures that the scheme is secure against quantum attacks,and supports the management and revocation of users.Aiming at the problem that computational overheads of the PKG is substantial in the current revocable IBE schemes.The outsourcing revocable IBE scheme from lattices is proposed for the first time.The scheme utilizes outsourcing technology and key segmentation technology.In the new scheme,most of PKG's overhead are delegated to a semi-trusted cloud server.The security of the scheme can be reduced to the difficult assumption of learning with error from lattice,and prove that the scheme is secure against adaptive chosen plaintext attacks.Finally,through the performance evaluation,the proposed scheme can more effeciently revoke illegal users and reduce the computational overhead of the PKG.