HLS test using AES-128k encryption with HLS (this is not possible with mpeg-dash). The key is not delivered with the playlist, which is supposed to be safer. Doesn't work on this Joomla installation because linking to files outside the system leads to a 404 not found (security measure). So, we can't show this is action here.
In any case, using the No Store -or With playlist option in Elastic Transcoder doesn't make any difference in terms of security. Once someone has access to the video or audio, they have access to the key. It may slow down some people but it doesn't fool download apps, alas. But encryption does protect your media at rest in the S3 bucket.