Positive Diagnosis

When a user tests positive, a limited set of Temporary Exposure Keys and their respective

ENIntervalNumber (describing when their validity started) are uploaded to the Diagnosis Server.

This set of Temporary Exposure Keys is limited to the time window in which the user could have been exposing other users (for example, the most recent 14 days). This subset of keys is referred to as Diagnosis Keys. If a user remains healthy and never tests positive, their Temporary Exposure Keys don't leave the device.

The Diagnosis Server aggregates the Diagnosis Keys from all users who have tested positive, and distributes them to all the user clients that are participating in exposure notification.

• Overview

• External Functions

• Key Schedule for Exposure Notification

• Positive Diagnosis

• Value Matching of Positive Users

• Privacy Considerations

• Test Vectors

• Revision History