IN-VEHICLE NETWORK SECURE COMMUNICATION METHOD, APPARATUS AND DEVICE

This application provides a secure onboard network communication method, an apparatus, and a device, to ensure that a freshness value is effectively synchronized within a vehicle lifecycle of a vehicle, and prevent a replay attack in onboard network communication. The device includes: a first processing module, configured to obtain an initial value of a first freshness value FV, obtain a second value based on the initial value, and refresh the initial value to the second value; a first sending module, configured to send a first message, where the first message includes the second value of the first FV; a first receiving module, configured to receive the first message; and a second processing module, configured to obtain an initial value of a second freshness value FV, and when a first condition is met, refresh the second FV to the second value, where the first condition includes a condition that the second value of the first FV is greater than or equal to a sum of the initial value of the second FV and a predetermined value.