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I want to at least prevent normal users to download my flash video.

What's the best way to do it?

Create a httphandler, add a token (e.g. timeid), set the cache control to no-cache so that only the users with correct token can view the correct video. Is that feasible?

It is the requirement from client that the video should not be downloaded by users and should be watched only in the particular website.

I want to know if this works: http://www.somesite.com/video.swf?time=1248319067

Server will generate a token(time in the above example) so that user can only have one request to this link. If the user wants to watch the video again, he needs to go to our website to get the token again. Is this okay to prevent novices from downloading?

I can't download this flash video by the downloadHelper firefox plugin: http://news.bbc.co.uk/2/hi/americas/8164177.stm

Updated (13:49 pm 2009/07/23): The above file can be downloaded using some video download software.

The video files of following Chinese sites are well protected (I can't download it using many video download software): http://programme.tvb.com/drama/abrideforaride/video/

Do you know how it is done?

Billy
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  • You don't say WHY you want to prevent it. Knowing why will help people suggest other alternatives than the solution you've chosen, i.e. preventing download. – Bernhard Hofmann Jul 17 '09 at 10:14
  • If it's on the internet, it's going to get downloaded wether you want it to be or not. Even if you were checking for a token, they would still have the entire thing, and could remove that part out. – Sneakyness Jul 23 '09 at 03:35
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    I know that whatever I do, the video will still be downloaded but the client requests us to do it as a form of due diligence so I add the "make it hard" in the topic. – Billy Jul 23 '09 at 03:40
  • I'd say you're better off watermarking it. – Sneakyness Jul 23 '09 at 05:52
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    Don't make it available for download. – Christoffer Jul 17 '09 at 09:40

9 Answers9

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I dont think there is an easy way to stop people from getting your videos if they want them,

there are plenty of plugins for firefox that allow downloading from even youtube and many places. And i imagine those plugins would disable any attempt you made to hide your videos.

not too terribly different than taking an image from flicker, they put a clear gif image over the image that you want to view, so that when you right click and save you get "the shield" image, however can be defeated by the lowly print screen button.

if you want casual users from getting your file, use a flash control and buffer a minute or two of your videos and make that flash authenticate with the server to get those files. that seems reasonable to me

Jim
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  • I think your final suggestion is the answer. You need to make a flash video that downloads the actual flash video. That way, if they save what they think is the video, they're just saving the video loader. But even this can be circumvented by running network monitors that show what is being downloaded. – Bernhard Hofmann Jul 17 '09 at 10:13
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    you should have seen my bosses face when i was doing HTML and javacript for a website,"I pay you to build my website and someone can just steal the code that easy? Can you make it so they cant see the code?", my answer, "Nope" – Jim Jul 17 '09 at 23:31
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This is how I like to tackle this issue.

This method works by creating a ticket to download the content over one http request...Another attempt to use the same ticket to download the content will fail, hence any extensions that attempt to download the content again or a user manually attempting to fail to do so, hence the flash player will be the only way to download the content. However there is one downfall for this approach, users will not be able to skip to a part of the video that has not been download...in some standard player implementation that may even stop the video from loading. Any ideas on this will be highly appreciated.

I begin by writing a PHP script that takes in a video_id, file_name, or a local path to your video file (Depending on the storage infrastructure of your video collection) in a GET request along with a unique hash value (a hard to guess and come up with probably generated with a secret key so it can be validated to be coming from our reciever (flash player), if the hacker send us a used hash or an invalid hash (does not satisfy our key), we will not send him the file). The PHP script then opens the video file and sends its content with the correct video mime type. for FLV the mime type is video/x-flv. It makes sure that once a unique hash has not been used before and is validly generated from your secret encryption key.

Then once the page with the flash player is loading we can give the .php file with the right get parameters as the video url to the video player. (If it is a prude player that only allows flv files you can always program your .htaccess file to parse .flv files as php script in the specific folder only, and rename your .php file as .flv and try your luck)...anyways...Also generate a hash key...perhaps you can take the servers current time and append it to a salt value such as another key known by both scripts, and encrypt this final concatenation with your secret key.

So once the video gateway php script will recieve a filename or hash key...it will decrypt the hash key and figure out if it is validly generated from teh sister script, and make sure not to send the video again to the same hash key...

For added security you can perhaps reset the secret key everyday using either a cronjob or bootstrap mechanism. To prevent duplicate use of hashkeys you can store them in a mysql database, file operations, or NOSQL (depending on your needs and infrastructure).

Make sure that the file is requested by the same user agent the hash key was generated for. In case the hacker trys to cURL or Wget your videos unused url before the flash player gets a chance to consume the hash key. In this case the hacker will have to imitate the browser's user agent or download the file using their command line tool as well...However please note that this is not your average champ.

Asad Hasan
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I don't think there really is an easy way to limit people from getting at it. Your sending them the video, that is how they are able to view it. Any user could just use FRAPS or a similar tool to copy the video from the screen as well.

If your worry is being copied and used elsewhere then you can watermark it or use a few other types of copy protection methods that will allow you to identify your work on other sites. If your worried about people copying it for personal use, then you really have no way of stopping it, you are sending it to them.

Edit: Due diligence would be to inform your customer of how easy it is to copy the work that they will be posting. Most clients have really no idea how easy it is.

Kelsey
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  • I know that whatever I do, the video will still be downloaded but the client requests us to do it as a form of due diligence so I add the "make it hard" in the topic. – Billy Jul 23 '09 at 03:43
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It sounds like you need to add authorization and authentication.

You could put the flash video under a different folder in your ASP.Net application and add a web.config file in that folder to deny access to unauthorized users. For example:

Then you need to enable authentication for your website. The simplest method is forms authentication. A trivial example with hard coded username and password is provided here.

There is loads that you can do with the authentication framework in ASP.Net I suggest googling a bit.

MikeD
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  • I don't need authentication this time. What I want is to let anonymous users watch the video but don't let them to download the video easily as requested by client. I just need to do it with due diligence in preventing un-necessary downloads. – Billy Jul 23 '09 at 03:04
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The only way to do this is with a trusted client, DRM and an encrypted source.

Your player opens up a connection, the user has a connection to the stream, you perform some magic authentication with their token and then transmite the encrypted data to them.

If you don't do this then anyone can download your video and save it out.

However with all that aside, someone can run screen capture, then save your video and do it again. This is again where the DRM comes in as one of the key features of the DRM in windows clients is that the buffer cannot be sniffed as it's on the protected media pathway.

I guess its a question of how to protect your revenue but dealing with pirates is always going to be a problem for software devs no matter what their business is.

Spence
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I have a solution that i'm gonna try for myself (as I have the same worries) but I know that it includes a lot of extra time and work...

Solution: using flash compress the video into an swf file. Before compressing add some AS code to the movie for authentication. suggestions for authentication:

1 test url 2 create a dedicated flash player that has handshake code checked by the video.swf

I like #2 better, and as an extra measure, you can overlay an id code over the video, so if someone captures the video using screen recording software, you'd at least be able to track the original source of the copied video.. and exact suitable retribution...

Nathan
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Simply you can't prevent it. But..you can make it difficult. Here some ideas come in my mind

1 First of all add your identifier to the video (always someone can download it)

2 The hard way... Add Ajax call back to server to check a random generated key that it will stored in the session every N seconds. After every post back clear the buffer of the player and start the video from were i was (using javascript). Use again JavaScript prevent the video source from downloading by "view source".

3 Handle all your videos in urls like http://www.example.com/viewvideo/1 OR ../?id=1. Add blank image overlay with transparent background. Serve the original video and a blank video somewhere on the page with normal extension and style attribute "display:none". (will create problems to some download helpers)

4 Everytime you serve a video CHECK if the request is from a browser (ie check UserAgent)

5 Cookie with some random value combined with the id of the video. Check it client-side and server side and then serve the video.

6 On focusout event hide the video with javascript. put a resume button in the flash and leave the frame unchange (like pause but with no original video in buffer).

7 Combine those methods

these are random generated ideas, not tested neither i say that guaranties no video downloading.

Jimmy Obonyo Abor
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Sanosay
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I have attempted two way to prevent the downloading but fails.

  • Using javascript to dynamically generate the object for flash.
  • Using the token idea proposed in the question.

What annoying me most is that a simple SAVE/AS from the firefox browser could easily bypass the tricks.

The only variable way so far is to using an empty swf file to load another swf file in. Combined with the token idea, it works.

Wudong
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in my answer you cant stop image/video theft but you can make harder for normal users but you can't make it harder for the programmers like us( i mean thiefs that knows little web programming) there are some tricks you can try:-

1.) Using flash as youtube and many others sites like http://www.funnenjoy.com does .

2.) Div overlaping or background pic setting (but users with little sense can easily save all resources by opening inspect element or other developer option).

3.) You can disable right click and specific keys like CTRL + S and others possibles with JAVASCRIPT but main drawback is that if user disable JAVASCRIPT our all tricks fail down.

4.)Save image in none online directories(if you have full access to web server) and read that files with server side languages like PHP every time when image / video is required and change image id time to time or create script that can automatically change ID after every access.

5.)Use .htaccess in apache to prevent linking of your images by others sites. you can use this site to automatically generate .htacess http://www.htaccesstools.com/hotlink-protection/

Ravinder Payal
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