Is there a utility that will encrypt a named configuration section (or just the connectionStrings section) in an app.config file in a similar manne
connectionStrings
app.config
You can try the following:
https://magenic.com/thinking/encrypting-configuration-sections-in-net
In short - rename the app.config file to web.config - the schema is identical, so aspnet_regiis works. Rename back to app.config when finished.
web.config
aspnet_regiis