Thanks! I actually brainstormed with a friend later that day on how it'd work and we finally came to a similar conclusion.
According to the spec, the phone only generates a new identifier when the MAC address changes or on a new day. But since it's generated in accordance to a 10-minute time window, that means you'd try to derive their key with all 144 possible time windows for that day. And if you find one of those ID's in your list of contacts, then you know you were in contact with someone infected.
According to the spec, the phone only generates a new identifier when the MAC address changes or on a new day. But since it's generated in accordance to a 10-minute time window, that means you'd try to derive their key with all 144 possible time windows for that day. And if you find one of those ID's in your list of contacts, then you know you were in contact with someone infected.