Public‐key coding system based on grey generation and braid group

PurposeThis paper attempts to construct a public‐key coding system using grey generation and braid group.Design/methodology/approachThe identification (ID) codes of both sides for communication are public for everyone and considered as public keys. Starting from the ID code of both sides of communication, the temporary secret key of communication can be obtained by the grey 1‐AGO algorithm first. Then the new formal common secret key can be obtained by using the element exchangeability of the braid group during the exchanging process of the temporary secret key between two sides of communication. The paper presents an exchange protocol of secret key based on grey data generation and braid group. It also constructs a cipher communication system by using Hash function based on the exchange protocol of secret key last.FindingsThe exchange protocol of secret key and the system of cipher communication which are proposed in this paper make use of the difficult problem of resolving disper se logarithm from generated code to ID code and the conjugate problem which is not ever resolved in braid group, which can ensure the security of the algorithm theoretically.Practical implicationsThe main steps of the exchange protocol and cipher communication system in this paper can be achieved through a computer program. They can be used in many communication processes on the internet.Originality/valueThe paper succeeds in realising both secret key generation and exchanging protocol of communication by using grey systems theory and braid group properties.