National Institute of Standards and Technology (NIST) developed ‘encounter metrics’ They have developed an encrypted method that can be applied to a device such as your phone to help with the ultimate goal of slowing down or preventing future pandemics. The method is also applicable to the COVID-19 pandemic. By labeling each encounter with a random number and not linking the encounter to the device the person is carrying, this makes it much harder for a cyber attacker to obtain that user’s identity.
Source: https://www.helpnetsecurity.com/2021/04/02/encrypted-method-encounter/