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how do I forward-lock images?Hi all, I'm trying to protect some important images which I don't want getting sent around the world from peoples phones. I've successfully added DRM protection to phones here in the UK via .dd and .dm files. However, I got a user on the Sprint network to test on a Samsung a900 but with the .dd files receives the error "the requested page cannot be displayed". Downloading directly works, as does downloading via .gcd files, but direct downloading is ruled out due to copyright reasons, and I'm unsure if .gcd method adds any forward-lock protection to the file like the .dd method does. I tried using a .gcd to download a .dd/.dm file, but that just gave the error "requested a handler (unspecified)". My question is, therefore, is there any way of protecting my content on the Sprint network? Or is this error with the .dd files only due to the handset maybe not supporting it or something? Thanks for any help :)
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how do I forward-lock images?
This is an interesting topic. What rights would you like the user to have? Other than "forwarding", what rights do you want denied? Is the user allowed to use the image as a wallpaper, caller ID, or just view it?
I would think the first step in protecting your content would be to prevent spoofing. For example, using a PC, I could emulate a Sprint phone to download your content. Once it's on my computer, I can do almost anything.
You also have to consider PDA phones like the Handspring Treo. They allow full access to the file system. You can't hide your content on those devices.
There is also software like BitPIM that allows file system access for almost all CDMA phones. It will be hard to protect your content from a tool like that.
If you only want to allow users to view the images (rather than use them as wallpapers, etc.) then you might consider a custom Java application that controls access to your content. You could distribute your images using some type of encryption that only your MIDlet would be able to unscramble. There are still some holes in such a scheme but it would certainly be a major roadblock for most users.
how do I forward-lock images?
Thanks for the reply - I'm basically just trying to stop people sending it to other phones or to their computer, due to a few privacy issues of the content downloaded. They can use it as wallpaper or whatever they want once on their phone.
The DRM I've used for other networks (i.e. forward-locking with .dd and .dm files) does the job, just Sprint either doesn't support it, or the handset I got a friend to try doesn't support it - no idea which!
Another bonus of the method I'm able to use on other networks is, even with downloading the images via an emulator (on the Nokia emulators at least, I'll have to check others), the image isn't viewable on a PC - only via the emulator as the jpg is in its encrypted state. There may well be a crack to the DRM, if not, it may just be a matter of time, but my thinking is most people using my site won't know how to do it, hopefully!
Unfortunately java is a bit out of my programming capabilities! So whilst that would probably be the best method of all, I don't think I'd be able to come up with such a program :(
Any idea if .gcd is the Sprint version of the DRM method I'm using for the other networks? i.e. do they automatically remove the ability to forward content downloaded via .gcd files to other phones by bluetooth/MMS, or is it just their way of allowing downloads?