During a long-term project in 2016, my team was tasked with reviewing the security features of a popular Soviet-era GPS satellite constellation. The client used it to obtain more exact positioning for workers who were attempting to locate underground utilities. After much digging and poring over the obscure technical diagrams, we discovered that this particular class of satellites did not encrypt GPS communications to a civilian end-user device — and it never would.
The constellation was not designed to support cryptography or data security of any kind. However, the communications channels were steady and reliable. The constellation was accessible to nearly every hand-held GPS device on the market. The coordinates were seldom (if ever) off — not even by a meter.
