1. What does key backup mean?
Our chat program not only encrypts the transports to and from the home server (in the data centre of the Bauhaus-Universität Weimar) but also allows the use of end-to-end encryption (E2EE). This requires the exchanging of cryptographic keys among all devices that want to communicate with each other on an end-to-end encrypted basis. Although this technical necessity sounds complicated and is indeed quite complex behind the scenes, it has now become very convenient for users.
The client generates multiple cryptographic keys and stores them on the respective device. If this is a tab in a browser, for example, there is a risk that this tab may be unintentionally closed. All encrypted content is then no longer readable. To prevent this from happening, the Bauhaus-Universität Weimar offers key backup on its home server, with secure storage of all cryptographic keys in encrypted form. The encryption is protected either by a security phrase or a security key that can be calculated from it.
2. Creating a security phrase
It is strongly recommended that you use key backup (with a secure security phrase that is NOT your university password). Sicherheitsphrase, welche NICHT Ihrem Passwort für den Universitäts-Login entspricht)!
3. Alternative: Generating a security key
Alternatively, you have the option to generate a security key instead of using a security phrase. This security key serves the same purpose as the security phrase. Furthermore, the security key is always created in addition to the security phrase and should be stored securely and retrievably as an emergency key. Ways of doing this include saving the key as a .txt file AND printing it out as a hard copy.
4. Requests for verification
If the prompt to set up the key backup is skipped, the next screen will look like this:
Key backup is strongly recommended to ensure worry-free usage of end-to-end encryption. For this reason, a small »Tooltip« will remind you to set up encryption even if you initially choose to skip the first prompt:
If you once again fail to comply with this request, you will receive a final warning if you deliberately log out. If a key backup is not set up at this point at the latest, it will not be possible to access any previously encrypted chats in the future. If the tab is closed, this may also correspond to logging out. Avoid this situation by setting up key backup.
