A New Cryptosystem Based on Positive Braids

The braid group is an important non commutative group, at the same time, it is an important tool in quantum field theory with better topological structure, and often used as a res-earch carrier for anti-quantum cryptographic algorithms. This paper proposed a difficult problem on a positive braid semi-group, and proved that the difficulty is not lower than the conju-gate search problem. Based on this new difficult problem, we pr-opose a new cryptosystem, which include a key exchange protocol and a public key encryption algorithm. Since our cryptosystem is implemented on a semi-group, it effectively avoids the analysis of attack algorithms on the cluster and makes our algorithm more secure.