To secure connections between the Data Exchange Windows components and their respective databases,
Enable encryption on the SQL Server instances that contain the internal databases (DDW Repository, Administration Database, Tracking Database, and DEMS database).
On the machines where you will install the Windows components (DDW, Runtime Administration, Runtime Service, and DEMS),
install the same certificate you used for the SQL Server instance in the Current User or Local Machine certificate store.
install the certificate chain of the Certificate Authority in the Trusted Root Certification Authorities.
For Runtime Administration, Runtime Service, and DEMS, enable secure connection to their respective database while installing the component. For more details, refer to Data Exchange Installation and Configuration Guide.
For secure connection between DDW and DDW repository, select Secure Connection when creating or connecting to a repository.