Besides HLS encryption, a very useful option to secure your videos is to restrict what domains are allowed to play your videos via the embed code. If you are concerned about your embed code being found and copied to other websites then you may want to whitelist your own domains so that your embed code works on those domains only.
You can configure this globally for every video in your account, or for individual videos.
Just to reiterate, this feature allows you to whitelist domains you own. So if you activate this feature, you would be adding your own domains so that your embed code works on those domains ONLY.
You can set a global policy so that all of your videos only work on the domains you whitelist. To set a global rule, click on the account settings in the bottom-left corner of the screen and then go to "Allowed Domains".
By default the toggle will be turned to the right, meaning your embed codes will work on any domain.
To set your own domains, first move the toggle to the left. Once you do that, you will see other options appear. Click on Add Domains:
Next, enter your own domain and then click on Whitelist This Domain. Be sure to enter only the top level domain (without www & https):
Once you do that you will see your domain listed. You can add as many domains as you want:
You can also set this policy for individual videos.
When editing a video, navigate to Video Settings >> Allowed Domains.
By default, the setting will be set to follow the Global Policy. Just switch that toggle to the left and then you can whitelist your domains:
Once you add your domains be sure to click Save.