[ralfd]

Currently there are 1.2 million active infections. Doesn’t this mean every smartphone in the world would need to download 17 MB per day?

If more cases would be tested in India or Africa or Sputh America a ten fold increase wouldn’t be unthinkable.

[jeremyjh]

No, my understanding is you only would download two weeks worth of keys when a new infection is reported. There is an assumption in any method of contact tracing that once people test positive that they are isolating themselves. If they don't, there is no reason to do the tracing since the virus will simply spread exponentially.

[tinus_hn]

The downloads are mediated by country specific apps. You don’t need numbers from the whole world.