More and more data is being stored in decentralised cloud systems not operated by the TU. A minimum requirement is the encryption of externally stored information.
If you need a free version for non-private use, the ITMC recommends the following: Cryptomator
Cryptomator provides an alternative to products like Boxcryptor, which do not allow non-private use in their free versions.
The SecurityInformationCentre (SIC) at TU Dortmund University is constantly testing further alternatives and will provide information about important innovations in cloud-stored data at TU.