Used to remind users who may have contacted coronavirus pneumonia-19 (COVID-19). You can enable MassNotify on your iPhone or Android phone to add another tool-19 in the battle to stop the spread of coronavirus pneumonia virus.
There are two main responsibilities: encounter record and infection report. The exposure notification only defines the encounter log, which is a decentralized architecture. Most infection reports are currently centralized and delegated to a single application.
In order to deal with encounter records, the system uses low-power Bluetooth to send tracking messages to nearby devices running the protocol to discover encounters with others.
The trace message contains a unique identifier encrypted with a daily key held by the sending device. These identifiers change every 15-20 minutes and the Bluetooth MAC address to prevent malicious third parties from tracking clients by observing static identifiers over time.
The sender's daily encryption key is generated using a random number generator. The device records the received messages and saves them locally for 14 days. If the user's infection test is positive, the last 14 days of their daily encryption key can be uploaded to the central server, where it can be broadcast to all devices on the network.
privacy
Enabling the system or publishing positive results through the system must obtain the user's consent, and it is forbidden to use the application of the system to collect location data. As an additional measure, these companies indicated that they would stop implementing the agreement on a regional basis once they determined that it was "no longer needed".
The Electronic Frontier Foundation expressed concern that the protocol was vulnerable to "link attacks". In this case, third parties with sufficient capacity to record beacon traffic can retroactively convert this information into tracking information, which is limited to the areas where they have recorded beacons. For example, once a set of daily encryption keys of a device is leaked, it is limited to users who have disclosed their coronavirus pneumonia-19 status.