

Accurate time is really important for computers for a lot of reasons.
Cell towers divide time into slots that different phones each get time in. If your time isn’t precise you might speed up or slow down which causes a slot to get a smaller or larger amount of time causing collisions. Handoffs between different towers need accurate timing to know exactly when one tower should release control of a handset.
NTP uses something called stratums. Basically stratum 0 is an atomic clock, stratum 1 is a device that talks to an atomic clock, but internally has its own time keeping. Then all the NTP servers moat people actually use are stratum 2+. Not only that, the Internet adds a ton of jitter because of how unreliable and unpredictable it is.
GPS satellites have atomic clocks on them making them stratum 0. They directly transmit that time. Thus receivers can become stratum 1 and have a very controllable, low jitter time source. Internet NTP isn’t precise enough. This kind of stuff requires microsecond precision.










It’s a question of security risk profiles.
Security ultimately often times comes with a tradeoff for user experience or privacy.
How does device integrity checks materially affect the security posture for theft when considering this system? Presumably the security checks for remotely unlocking a car is based around credentials and authN/authZ for the unlock service call?
Enforcing client side security has entered the picture recently, but a lot of it comes from security checklists from people saying did you add this check? Sure adding a device integrity check may stop at least one malicious actor, but is it worth the cost? To most companies, they’re going to say they don’t understand or care about the impact.
They could just go back to key fobs since those can’t run arbitrary code.