jerryb:

DS248:

One weakness in the whole system is that the design is based on recording entry to 'public' places whereas for many people, most contact with other people will be at private addresses, etc.

Similarly open spaces like parks, kids playgrounds etc.  One place I do go (less regularly than I should!) is around Orewa Estuary for a run.  In the age of Delta perhaps locations like these need QR codes though not certain how it would work with almost unlimited entry point (not going to stop and scan partway through a timed run).

Better still (& at the risk of a hostile reception), why not just make the system more secure and turn on location tracking in the app?  All data simplified to the min required and properly secured.

Isn't that what the Bluetooth mode is for? (Genuine question)
- You're in a park and you walk past someone coming the opposite direction.
- You both have the app, with the Bluetooth feature switched on.
- The phones do their little handshake and each of them records the other's ID.
- The other person tests positive a few days later. - Their Bluetooth log (in the app) shows that the two phones were in each other's vicinity.

Isn't that how it works?