Signed URLs are tokenized time based urls to limit downloads and viewing to a determined time stamp Video Protection
Please watch this video to get a clearer picture with how best to use signed / time based urls on Gumlet.
Workflow (and points to note)
0:23 The Embed URL & Embed code will not work with signed URLs ON
0:50 Mp4 output format will not secure playback URLs
1:21 Signed URLs are best used with HLS playback URLs
Related video : Using Signed URL On Gumlet Video