Building a system that allows users to see a video only once

My client wants to distribute a video to some people, specifically car dealers, but he doesn't want the video to end up on Youtube or something like that. Therefore he wants the recipients of the video to be able to see it only once. My idea to implement this is:

• Generate a unique key per viewer
• Send each viewer a link to a page with a Flash based开发者_JS百科 video player, with their key in the URL
• Have Flash get the video from the server. On the server the key is checked and the file sent (using php's readfile or something equivalent). Then the key is invalidated.

I was thinking this wouldn't take more than a day to build.

I know that if you want somebody to be able to play something, you implicitly give them the power to record it as well, but the client just wants me to make it as hard as possible.

Do you think this is secure enough for the intended audience? Anything else I can do to add some security without exceeding the development time of 1 day? I'm also interested in ready made solutions, if they exist.

---

I would add another security to this. To be sure that the only way It can be recorded is with a screen recorder and not a flash get plugin, you can set a opaque layer on the video and another flash who is outside of the player swf that send a command to make the layer alpha transparent, so when the download the file using a plugin they received a black video and if the record using camstudio or something else they lose quality.

---

One supposedly commonly used ready made solution is Lighttpd's mod_secdownload. It can be used in streaming applications like Flowplayer.