we can’t restore a backup on a different instance `without Certificates`. We’ve to restore the `Cert` from `Source Server` , then we should be able to `restore` the `Database` from the `Backup`.

obviously your certificate & Master key are required for restore.
 

As `MSSQLTREK` Blog <a href="https://mssqltrek.com/2011/09/02/sql-server-encryption-part4how-to-restore-an-tde-enabled-database-encrypted-backup/">Here</a> To restore the Certificate from source(And you have to create a DMK(Database Master Key) on destination if you don’t have one), the rest is just performing your normal DB restore process what you do on any other non encrypted user database(s). 



Create a Master Key(You don’t have to do this if you already have DMK) and Create a certificate from the Cert Backup and providing Private Key file and Password to decrypt it.


> Backup files of databases that have TDE enabled are also encrypted by
> using the database encryption key. As a result, when you restore these
> backups, the certificate protecting the database encryption key must
> be available. This means that in addition to backing up the database,
> you have to make sure that you maintain backups of the server
> certificates to prevent data loss. Data loss will result if the
> certificate is no longer available.

For your further ref <a href="https://mssqltrek.com/2011/08/31/sql-server-encryption-part3gotchas-a-tde-enabled-database/">Here</a> and <a href="https://www.simple-talk.com/sql/database-administration/transparent-data-encryption/">Here</a>

**Note** : If you enable TDE on any Database on your Instance, Your TEMPDB is automatically Encrypted as well. Soo…there’s a high possibility impacting other Databases which are actually not using TDE feature while you are in the process of enabling TDE!!!