In Canada the chief aviation security legislation lies within the Aeronautics Act. To a casual observer however, it would appear very limited, but most of the measures are confidential and consequently are difficult to access by the general public.
In the U.S., foreign air carriers are regulated through the Model Security Program (MSP).
In addition in Canada and the U.S., two Advance Passenger Approval Systems are in place; Passenger Protect and Secure Flight. Internationally an Annex 17 to the International Civil Aviation Organization's Chicago Convention deals with International Air Security.