Communications Security Establishment
Under the still-classified "UKUSA agreement", Canada, Australia, New Zealand, the U.K., and the U.S. agreed to collect SIGINT in different parts of the world, and share the material, with overall analysis remaining a national responsibility. Even with analysis, there is significant cooperation among these countries.
CSE, headquartered in the Leonard Tilley Building in Ottawa. is responsible for Canada's SIGINT.various forms of signals intelligence, including traffic analysis and cryptanalysis. It has SIGINT collection stations scattered throughout Canada, in positions to receive signals from various parts of the world, positions dictated by the technical characteristics of radio signals to be intercepted.