Communication key security isolation method and system based on hidden physical layer signature

The invention relates to the technical field of communication, in particular to a communication key security isolation method and system based on hidden physical layer signature, which can generate a physical layer key sequence as an access layer key without estimating a channel by depending on a pre-agreed sending sequence. A security factor which is independent of a non-access layer and is strongly related to a terminal position and a sending sequence is introduced, so that access layer security protection starting from initial negotiation is realized; a physical layer signature of a message is derived by using an access layer key, and functions of message source identity authentication, message integrity and confidentiality verification, anti-repudiation and the like are realized with relatively low calculation cost; and a hidden communication mode that a chaos spread spectrum sequence is generated through a physical layer secret key to carry out spread spectrum communication is adopted, so that anti-inter