Abstract:

Multivariable publickey cryptography and coding cryptography have the ability to resist quantum computation attacks and high efficiency of use, both of which are therefore reliable candidates for anti-quantum cryptography. In the multivariable public key cryptography, the construction of the central mapping is very important. Because the coding cryptography has similar matrix operations with multivariate cryptography and the ability of data compression, it is a hot direction to combine coding cryptography with multivariate cryptography. This paper combines the LRPC code in the coding with the Simple Matrix improvement scheme in multivariate cryptography to construct a new scheme. Compared to the Cubic Simple Matrix scheme, the ciphertext expansion rate is reduced by 50%, and the advantages of the coded password are combined. Since the new scheme is constructed on the basis of the improved version of Simple Matrix, it is more flexible when selecting LRPC codes than the previous signcryption schemes based on LRPC and multivariate cryptosystem. In addition, under the random oracle model, the new scheme was proved to satisfy IND-CPA security.

Key words: multivariable public key cryptography, LRPC, central mapping, security analysis