[ateevchopra]

There are 2 different aspects of privacy in Contact Tracing technology. One is regarding device-to-device contact and another is device to cloud. In case of device to device, there's no knowledge if it shares your personal info to other phones.

If a person is found COVID positive, all the traced contacts will be under high-risk. In that case the details are sent to the cloud/governments to take apt precautions and to quarantine the individuals.

Even Apple/Google's contact tracing app send your personal data to the cloud and "works closely" with governments.

Source: https://www.apple.com/in/newsroom/2020/04/apple-and-google-p...

[marksomnian]

The difference being that in the Apple/Google implementation, the app only sends anonymous tokens, with nothing tying them to anyone the infected met. Then their contacts download the full list of these tokens from the cloud and match them against their local history of tokens. (Again, key part being that this matching happens locally, not in the cloud.) The government never gets involved except in allowing the infected to upload their (anonymous) history.