Assessing the risk of infection
TAN confirmation code is valid for three hours
The epidemiological service obtains a random confirmation code (teleTAN) online. It sends this code to app users who tested positive. The user decides whether they will enter the code in the app, so that the app can warn others of their infection. The confirmation code is valid for three hours. When the confirmation code is entered, the app sends the code to the verification server, which checks if the code has been issued by this server. Only hashed confirmation codes (teleTAN) are stored on the server.
This is one of the crucial steps with which every user of the #OstaniZdrav app can prevent the uncontrolled spread of the infection. We call upon users to enter their code in the app as soon as possible after receiving it.
Entry and verification of confirmation code
When the confirmation code is entered, the app sends the code to the verification server, which checks if the code has been issued by this server. Only hashed confirmation codes (teleTAN) are stored on the server. When it is established that the confirmation code (teleTAN) is valid, the verification server generates a registration token and sends it to the app. After consent is given for the transmission of the user’s daily keys, the app sends the registration token to the verification server, by which it requests proof of infection. If the confirmation code (teleTAN) and the registration token match, the verification server sends the proof (TAN) to the app.
Data on infected people are deleted after 14 days
The app sends to the app server all its daily keys (TEK) and proof (TAN) that these are the keys of an infected person (diagnosis keys). All diagnosis keys are available on the server. Diagnosis TEKs are deleted 14 days after they are generated.
Periodic checking of data
The app periodically connects to the app server and downloads the data on diagnosis keys. It also downloads criteria for calculating exposure. The app then checks whether the stored rolling proximity identifiers of other app users match any of the diagnosis keys downloaded from the app server.
Calculation of risk
If the system detects a match, the risk of infection with the novel coronavirus is assessed. The level of risk depends on the proximity, which is calculated based on the strength of the Bluetooth signal, and the duration of exposure. Depending on the risk assessed, the app displays a notification and the app's start page turns green or red.
#OstaniZdrav detects and warns of low and high risk
When the app detects a low risk, its colour scheme turns green and it informs the user:
- that the review of their contacts on the relevant day did not show any encounters with infected people, or that according to risk assessment such encounters did not exceed the set threshold,
- about general recommendations for preventing the spread of the novel coronavirus, with regard to respecting and implementing hygiene measures and with regard to maintaining safe distance in contacts with other people.
When the app detects a high risk, it turns red and displays the following messages:
- Avoid all unnecessary contacts with other people, in particular persons at high risk of severe COVID-19, such as older people and patients with chronic diseases. We advise you to use a protective mask in enclosed spaces where it is impossible to maintain sufficiently safe distance from other people.
- Monitor your health. If you have any of the following symptoms, stay at home and call your chosen doctor or out-of-hours doctor:
- malaise, cold symptoms, cough, fever, shortness of breath, headache, muscle pain, loss of smell or taste, or sore throat.
- Continue to apply the general measures for preventing the spread of infections.
- General information on COVID-19 is available on the website of the National Institute of Public Health and on the GOV.SI website.