Thank you for your help. From comparing what you presented and some MS documentation, I believe I now have a clearer picture. I always thought of the restore as happening only for the db on the current machine, but now see that after moving db over, would have to use encryption key of machine that the db was originally on. Restoring appears to use the key to create another key. I made sure to backup the encryption key again - this time on the new machine, after the restore occurred.

I did the following, which worked:

1. Backed up dev db (copy only), and made sure the encryption key for was backed up

2. copied backup over to prod server so could use

3. stopped reporting Server instance, restored prod db with backup taken, and re-started Reporting Server instance

4. Opened SSRS Config Mgr on prod server & restored using the key I had backed up from dev. I did get the following error:

Microsoft.ReportingServices.WmiProvider.WMIProviderException: The feature: "Scale-out deployment" is not supported in this edition of Reporting Services. (rsOperationNotSupported)

As we don't use Enterprise Edition, this is rather strange. However, the dev server happened to be joined as well as the prod server when I looked at the Scale-out-Deployment page of the config mgr. I removed dev and afterwards was able to restore.