This is my summary of how I interpreted it works:
- A [Tracing Key] is stored locally in every device.
- A [Rolling Key] gets regenerated every day based on the [Tracing Key]
- A [Proximity Identifier] gets regenerated every 15 minutes and broadcasted to other bluetooth devices.
- The Contact Tracing Bluetooth Specification does not require the user’s location; any use of location is completely optional to the schema.
- Other devices save the [Proximity Identifier] locally.
- History is stored for a couple of weeks
Some questions about how I interpreted the rest:
- The device wakes up once a day and downloads the list of identifiers that have been known/reported to have COVID. It compares on device that you are on that list. Q: Wouldn't this list be insanely long? More so if it doesn't have any concept of location?
- If you have COVID-19, you can report to the servers that you were found to have it. Your rolling identifiers gets uploaded to the "cloud server". Q: Which "cloud server"? Whose cloud server?
Any clarifications are strongly welcomed :)
- If diagnosed with COVID-19, users consent to sharing Diagnosis Keys with the server.