In the web area, you can recognize encryption by the protocol name "HTTPS". The server needs a certificate to be able to identify itself as 'legit' to the requesting client. 

Since the end of 2015, there has been a free certificate authority called Let's Encrypt. This is represented in the common browsers and e-mail programs, so visitors to websites that are operated with Let's Encrypt-based certificates do not receive any security warnings, as would be the case with so-called self-signed certificates. The RRZK also uses this service for the majority of the web servers it operates, so that certificates are automatically renewed and in some cases also generated. Newly created web presences, which are administrated by us (e.g. web projects, TYPO3 pages), automatically receive a certificate from Let's Encrypt and are thus accessible via https(-only).

If you operate your own web server, for example a virtual machine at the RRZK, we recommend using Let's Encrypt for this as well.