| Digital signature is an indispensable component of public key cryptosystem.It is widely used in the fields of communication,electronic commerce and national defense because of its non-repudiation,data integrity and unforgeability.At present,the security of most digital signature schemes is based on traditional number-theoretic assumptions,such as Integer Factorizatin and Discrete Logarithm Problem.With the development of quantum computing,these traditional complexity assumptions would be broken.Therefore,it is necessary to design anti-quantum digital signature schemes and the lattice-based digital signature scheme is an important research direction.This thesis focuses on the lattice-based on-line/off-line signatures and the latticebased sanitizable signatures.The lattice-based chameleon hash function is used in the design of these two types of digital signatures.The main research results are two-fold:1.Shamir and Tauman used chameleon hash functions to develop a new paradigm called hash-sign-switch,which can convert any signature scheme into a highly efficient on-line/off-line signature scheme.Inspired by their work,we design a latticebased chameleon hash function.Combining with the signature scheme proposed by Zhang et al.in 2016,we propose a lattice-based on-line/off-line signature scheme(LBOSS).2.Since the concept of sanitizable signature was proposed,its expansion and deformation have been proposed by other scholars.However,little attention has been paid on anti-quantum sanitizable signatures.Another work of this thesis is that a lattice-based sanitizable signature scheme(LBSSS)is proposed by employing our lattice-based chameleon hash function. |
