Three-party Key Exchange Protocol Based on Tropical Algebras

Three-party key exchange protocol allows three parties to agree a new secure key for communication by an contributional protocol on insecure channel, so as to ensure three-party secure communication on public channel. Based on D.Grigoriev's research, the three-party key exchange protocol is proposed, which is based on Tropical algebra. This protocol has following advantages. It uses new Tropical algebra as construction tool. Addition in Tropical algebra is defined as taking the minimum while multiplication is ordinary integer addition. This protocol is different from other three-party key exchange protocols which contain one trusted server and two parties. Three parties contribute equally in key exchange. Security of the protocol is analyzed, and it can resist linear algebra attack. This method is simple to implement and with good efficiency.