Security systems and methods with random and multiple change-response testing

Abstract

A diagnostic system for a vehicle includes a first processor module and a second processor module. The first processor module includes a first microprocessor and memory. The second processor module includes a second microprocessor and memory. The second processor module: selectively transmits a first challenge to the first processor module for a first challenge-response test; selectively transmits a second challenge to the first processor module for a second challenge-response test; selectively transmits a third challenge to the first processor module for a third challenge-response test; selectively transmits a fourth challenge to the first processor module for a fourth challenge-response test; and selectively diagnoses a fault based on responses of the first processor module to the first, second, third, and fourth challenges. The first, second, third, and fourth challenge-response tests are each different types of challenge-response tests.

Dependencies are inferred from the claim text.