IN-VEHICLE NETWORK OTA SECURITY COMMUNICATION METHOD AND APPARATUS, VEHICLE-MOUNTED SYSTEM, AND STORAGE MEDIUM

An in-vehicle network OTA security communication method and apparatus, a vehicle-mounted system, and a storage medium. The method comprises: sending a communication request to a sub-processor, and receiving a first random number generated by the sub-processor and a check code generated based on the first random number and a root key (101); after the check code is verified to be correct, generating a second random number, concatenating the second random number and the first random number into a random number set, and sending to the sub-processor the random number set and a check code generated based on the random number set and the root key (102); after receiving the information that the verification by the sub-processor succeeds, deriving a temporary communication key on the basis of the random number set for encrypted communication with the sub-processor, and issuing an upgrade package to the sub-processor (103); and after the upgrade package is sent, ending a session and invalidating the temporary key (104)