How to use the application čTečka

How does the application čTečka work?

The guide on the application čTečka

This is a step-by-step guide on how to use it.

1. Terms of use and privacy policy

First, you must agree to terms of use and processing of personal information by clicking on the button I AGREE at the bottom of screen.

You can find more information on the terms of usehere.

2. Main screen

Click the blue button SCAN QR CODE to scan a code by the camera on your mobile phone.

Click the white button UPDATE PARAMETERS to download an updated version of the validation regulations. The regulations are also downloaded automatically every 24 hours.

Click on the phone icon CONTACT: 1221 to call the covid support line where you can talk to an operator. This call is free.

Click on the gear wheel in the top right corner for the information on how to use the application and terms of use.

3. QR code scanning – Allowing camera access

Before scanning a QR code and for the first time you use the app, you should allow čTečka access to your mobile phone camera. This screen differs depending on a specific type of your device.

4. QR code scanning

Place the QR code of the certificate in the viewfinder indicated by a lighter colored frame in the center of the screen.

A QR code looks like this:

It is usually located in the top right corner.

You can scan printed paper certificates or their digital form from a screen of any other device.

You can cancel the process by clicking on the button CANCEL SCANNING. You will then return to the main screen.

5. Valid vaccination certificate

If verification is successful, the screen will turn green displaying the name and date of birth of the certificate holder.

Click on the button DETAILS to see detailed information on the valid certificate.

Click on the button NEXT SCAN to start scanning another QR code.

Click on the white cross in the top left corner to return to the main screen.

Click on the question mark in the top right corner for the information on how to use the application čTečka.

6. Valid vaccination certificate details

On the screen Details, you will see the following information on a valid certificate:

• name of the certificate holder
• date of their birth
• validity of the certificate

Information on the vaccine type will be displayed under the valid vaccination certificate.

Click on the button NEXT SCAN to start scanning another QR code.

Click on the white arrow in the top left corner to return to the main screen.

Click on the question mark in the top right corner for the guide on the application čTečka.

7. Invalid vaccination certificate

If the verification is not successful, the screen will turn red displaying the name and date of birth of the certificate holder.

Click on the button DETAILS to see detailed information on the invalid certificate.

Click on the button NEXT SCAN to start scanning another QR code.

Click on the white arrow in the left top corner to return to the main screen.

Click on the question mark in the top right corner for the guide on the application čTečka.

8. Invalid vaccination certificate details

On the screen Details, you will see the following information on a invalid certificate:

• name of the certificate holder
• date of their birth

Information on the vaccine type will be displayed under the vaccination certificate.

Click on the button NEXT SCAN to start scanning another QR code.

Click on the white arrow in the top left corner to return to the main screen.

Click on the question mark in the top right corner for the guide on the application čTečka.

FAQ – frequently asked questions on the application čTečka

Why are the mobile applicationsfor Digital COVID certificates called Tečka and čTečka?

The names refer to the campaign “udělejme tečku za epidemií” (let’s put the pandemics behind us) by the Ministry of Health of the Czech Republic.

What can the application čTečka do?

The application čTečka for verification of Digital COVID certificates (in EU standards terminology “Verifier”) provides the following:

• Downloading configuration – signature keys (EU countries) and validation regulations (Czech Republic only) from the IHIS CR server. It occurs once every 24 hours.
• Scanning QR codes, verifying electronic signatures, verifying validity according to the validation regulations. It occurs offline.
• Providing an overview and detailed information on the certificate.
• Retrieving and providing information from the original vaccination certificate, it will be, however, marked as invalid (not in compliance with EU standards, its validity is not verified)

When will the application Tečka be available and what will it do?

Tečka application for downloading and presenting certificates (in EU standards terminology “wallet”) will be available by the end of June and will include the following:

• Login via NIA the first time, and later only via a fingerprint, face recognition or a PIN
• An alternative login via a one-time SMS passcode (as at ocko.uzis.cz) the first time, and later only via a fingerprint or face recognition, or a PIN
• Supporting viewing certificates of multiple people
• Uploading existing certificates from ocko.uzis.cz
• Scanning certificates off paper or a displayed QR code of the holder or other people
• Converting an original vaccination certificate into the EU format
• Showing certificates with validity assessment in compliance with the validation regulations, which occurs offline.
• Providing an overview and detailed information on the certificate
• Downloading configuration – signature keys (EU countries) and validation regulations (Czech Republic only) from the IHIS CR server. It occurs once every 24 hours.

On what phones do čTečka and Tečka work?

The mobile applications are available for mobile phones with Android operating system of version 6 and higher, and iOS operating system version 12 and higher.

The mobile applications are distributed via Apple Store and Google Play Store. They cannot be installed on Android phones that do not support Google Play Store, e.g. the latest Huawei phones.

How to switch the language of the applications Tečka and čTečka?

The applications support Czech and English. The language of the applications is selected according to the language setting of the operating system by default. iOS allows changing the language of the application in the Settings – scroll down to the settings for separate applications, select Tečka or čTečka and you can change the language.

How do I find the applications in Apple Store and Google Play Store?

The names of the applications correspond to frequently used words, therefore we recommend searching the applications using a combination of words, e.g. ”čtečka covid” or “čTečka Ministerstvo zdravotnictví” if the search does not show the applications among the first options when their names are entered.
The čTečka application’s icon is a white circle inside a yellow box saying ČTEČKA.
The Tečka application’s icon is a yellow circle inside a white box saying TEČKA.

Can the application retrieve information from certificates of all EU countries?

Yes, it is possible since the transition period in June 2021 for all the countries that provide their signature keys to the centralized exchange system DGCG. čTečka checks the validity of foreign certificates according to the Czech regulations (number of days after the first/second dose, etc.)

Why is the original version of the vaccination certificate always shown as invalid?

čTečka cannot verify authenticity of an original certificates (whether it truly is a QR code created by IHIS CR and not a hacker), but it can display the information on the certificate. čTečka does cannot convert original EU certificates to new ones, this function is not determined for frequent repetitive check. Conversion of old certificates into new ones will be supported by the application Tečka in the future.

What is Update Parameters?

Validity verification parameter update– signature certificates of EU countries, current validity regulations (number of days after the first/second vaccination dose, etc.). The parameters are updated when the application is open if they are older than 24 hours or when you click on the button “Update parameters”. The application can still be used with outdated parameters.

Does the application need Internet connection?

Only for updating validation parameters, but not for the actual verification of certificates.

Does the application store information from certificates?

No, it only temporarily displays them on the screen. You can find more information on personal data protection at https://ockodoc.mzcr.cz/napoveda/ctecka/cz/podminky-pouzivani

What does the error “Could not recognize the QR code format” on the page with the camera mean?

The application recognized that it is a QR code, but the data in it does not have correct structure according to the EU standard. It is either a QR code for different use or it has a poorly structured EU certificate that cannot be scanned in full or be verified.

What are reasons for a certificate to be invalid?

• it contains an incorrect data format; in that case it cannot be scanned at all and the data from it cannot be retrieved
• the electronic signature cannot be verified – specific reasons are coded in SIGxxx error codes
• it does not comply with the validity regulations (number of days after the first/second vaccination dose, etc.)
• it might be an original version of vaccination certificate issued before 1.6., which is always marked as invalid

The reason for a certificate being invalid is always listed in the screen Details.

Even for an invalid certificate, if it is technically possible to obtain information from the certificate, the information from the certificate is listed on the screen Details.

What do the separate reasons for a certificate being invalid listed on the page Details mean?

The reasons for a certificate being invalid shown on the Details screen are as follows:

• The electronic signature of the certificate cannot be verified – see the following question
• The certificate is invalid – revoked – the certificate was marked as invalid by the issuer, it was probably issued by mistake
• The validity of the vaccination certificate has not yet started or has already expired – check the vaccination date and the validity period listed on the Details screen – they are calculated based on the validity regulations (22 days after the first dose, etc.)
• The validity of the certificate of past disease has not yet started or already expired – check the date of the positive PCR test and the validity period displayed on the Details screen – they are calculated based on the validity regulations (180 days after the test, etc.)
• The test certificate is no longer valid – check the date of collection and the validity period displayed on the Details screen – they are calculated based on the validity regulations (72 hours for an AG test, etc.)
• It is the original version of a vaccination certificate – it is always marked as invalid, see the answer above.

What is the meaning of the error codes SIGxxx, when an electronic signature cannot be verified?

In the vast majority of cases, electronic signature verification error codes indicate a technical problem with the content of a QR code caused by its issuer.

However, they may also indicate an attempt to forge a QR code, and the electronic signature’s purpose is to protect QR code from it.
The detailed technical meaning of the separate codes is as follows:

• SIG001 – Information on expiration is missing in COSE
• SIG002 – COSE has expired
• SIG003 – KID is missing in COSE (public key identifier)
• SIG004 – Active signing certificate for KID could not be found
• SIG005 – Failure to extract the key from certificate’s data
• SIG006 – Wrong signature data in COSE
• SIG007 – Failure to verify the signature

The error SIG002 refers to expiration date of technical validity of the certificate, set by the certificate authority (it is not connected to the validity of health condition certificate). The validity is set to 1 year for certificates issued in the Czech Republic.

The error SIG004 means that the application could not find the relevant signature key in the parameters downloaded from IHIS CR. It might be a technical problem on the side of the certificate authority, a problem in communication transferring among the issuing countries and the Czech Republic via EU communication gateway, or a problem in updating parameters between the application and IHIS. In some cases, it can be resolved by pressing the button Update parameters.

The application support cannot diagnose an error without the problematic QR code, provided, for example, as an image by email, etc.

Why is the name mentioned twice in the certificate details?

The first time it contains diacritics (or is written in the national alphabet of a given state), the second time it is an international transcription without diacritics.

What will the application want to have access to on my phone?

To camera only.