Embodiments of the present disclosure monitor certificates or other credentials loaded to various components and systems of a vehicle. A set of information identifying credentials that are expected to be present and/or in use can be saved. Periodically, on request, or upon the occurrence of an event or condition, checks can be performed on the credentials individually or in the aggregate using the saved information to determine whether the certificates present and/or in use are those expected or if a change has occurred. If a change is detected, i.e., a difference between the current set of certificates and the saved set of information, the network security system can take some action. The action, depending on the nature of the change detected, can vary from recording and/or reporting the condition up to and including isolating or even disabling a particular component or system on which the changed certificate is used.