Yes. At DESelect, we place a high value on security.
In terms of securing our integration with Salesforce Marketing Cloud and performing authentication, we follow the Salesforce API integration security guidelines.
In terms of data processing, we only store metadata (data extension names, user name,…) but not actual data (the records within a data extension). That means we are rather “lightweight” from a data processing point of view, as we do not store your actual customer data.
For more information check out our security documentation.