The CU Key mobile app was developed to increase the security of the CAS user account.

With thanks to that, users can easily and reliably verify their identity when signing up for university services.

The app provides a modern method of two-factor authentication that greatly increases the security of university systems that require a CAS login.

The CU Key is thus an important step towards enhancing the security and data protection of the entire academic community.

At the same time, the CU Key uses a similar principle of secure login that you know from mobile banking. This makes the login not only secure, but also simple and familiar to use.

For more information on legislative requirements, employee privacy protection and multi-factor authentication options, visit the CU Intranet Legal grounds for MFA through CU Key.

1.Visit website ldap.cuni.cz/mfa and log in.

• Select "Mobile phone application" among the available options:

  
  

  

  
  

• Choose a QR code based on your mobile phone operation system and scan it to download the app.

  
  

  

  
  

2. Open the CU Key mobile app

• Enable notifications

  
  

• Click on the "Login" button and enter your username and password to CAS

  
  

  

  

  
  

• Create a PIN code for unlocking the app

  
  

  

  

  
  

• You will see "Renewal codes" for account renewal.

  
  

  Please write down these codes on a different device so you can use them in the event of loss or theft of your mobile phone.

  
  

  You may also enable biometric authentication, e.g. fingerprint or FaceID, if you use it on your device.

  
  

  

  
  
  

  

  
  

3. If the registration was successful, the date and time will be shown for the selected method.

You can now click on the "Turn on" button to start the verification with the second factor.

• After clicking the Mobile phone application option, you can check the emergency scratch codes again via the "Show scratch codes" button.

  Please note that each code can be used only once.

  
  

  

• The Export button allows you to transfer data to a third-party TOTP (time-limited one-time password) application.

  
  

  

  
  

  After loading the QR code, your phone will prompt you to select the application (Google Authenticator, Microsoft Authenticator, FreeOTP, etc.) that you have installed. More information >

4. Visit website that requires CAS login and two-factor authentication, e.g. servicedesk.cuni.cz and log in.

Select a method for the second verification factor:

• You will receive notification on your mobile phone about a new request for authentication. Access the app using PIN code or biometrics and confirm the request.

  
  

  

  

  
  

The Remember Device window appears. This setting is used to make Two-Factor Authentication remember the browser on your device from which you are logging in.

• Corporate or personal computer: Choose Remember – you will not be prompted for authentication for another 14 days.

• Public device (e.g. classroom, internet cafe): Choose Skip.

Note: Authentication may be required earlier (e.g. for forced account authentication or after browser update).

In addition to the CU Key mobile app, we recommend setting up a backup two-factor authentication method.