You can store encrypted values in your ASP.NET Core configuration file and seamlessly decrypt the values as you retrieve them. But there are, at least, two issues that you'll need to address.

Take advantage of connection resiliency in EF Core to detect errors and retry commands and enable your ASP.NET Core application to overcome transient faults.

Encrypting data with the Data Protection API in ASP.NET Core Now that the Data Protection API has been installed and configured in your project, you can take advantage of the API to protect data.