We recently learned that Google had launched a very interesting tool in the United States to find COVID-19 vaccination points, in a bid, by the technology giant, to continue helping society in the fight against the current coronavirus pandemic.
On that occasion, it is a really useful tool for US citizens to not only find COVID-19 vaccination areas, but even offer them the possibility to schedule vaccination appointments or obtain information.
Something similar to what the company already offered in the United Kingdom, in which English citizens who wish to can use a new search function for some time with the intention of finding information about the vaccine and discovering which ones have been authorized in your location.
But this time we have learned that both Google and Apple have developed a complete COVID-19 contact tracing system , which works without the need for the user to install an application (as in fact, in our country, it happened so far with the ill-fated but interesting COVID Radar).
In the United States, states such as Virginia, California, Colorado, Maryland, Minnesota, Washington or Nevada have enabled a COVID-19 exposure notification service without applications for iPhone users , which will not require the installation of any exposure notification app , but activate notifications directly in the device settings .
It is an exposure notification system created jointly by Apple and Google for their iOS and Android operating systems, which these companies have finally updated to work without the need to install an app (something that has proven to be of little use and draft among users in the last attempts).
How does this notification system work?
Since Bluetooth is compatible with billions of devices, it is an indispensable element in this tool. For this, the Bluetooth Low Energy protocol (also known as Bluetooth LE) is used, optimized for energy efficient communication between small devices.
To create the notification app using Bluetooth LE, developers could assign each device a permanent ID, causing all phones to broadcast it on an advertising channel. And finally, they could develop an app that receives the identifications so that each phone can keep track of close encounters with other phones. However, it would be an obvious violation of user privacy.
Therefore, to solve the problem, each device emits a long random number , which is changed frequently. Other devices receive these numbers and store them if they were sent from too close. This way, by using long, unique random numbers, no personal information is sent over Bluetooth LE.
Although both companies follow this principle, they have added some cryptography, as each phone generates a unique tracking key , which is kept confidential in the terminal. Thus, on a daily basis, the tracking key generates a new daily tracking key.
Then, every 10 to 20 minutes, the daily tracking key generates a new identifier, which is ultimately what is transmitted to other devices.
When someone tests positive for COVID-19, it is possible to reveal a list of their daily tracking keys, usually from the previous 14 days. The phones then compare the positive COVID-19 identifiers with their own identification records they received from nearby phones. A match reveals a possible exposure to the virus, without identifying the person originally affected .
Therefore, the exchange of information is always anonymous , useful to discover if we have recently been in contact with a positive for COVID-19, but without knowing exactly who it would have been.
As we can see, the system designed jointly by Apple and Google could be the key when it comes to alerting those users who have been exposed to the coronavirus without knowing it while protecting their identities. All this without the need to install an application.
