   "Time-bomb" media
  If you've ever attended a pre-release screening or certain special events surrounding a movie, sometimes you're given what's called a "time-bomb" DVD. These DVDs have an unusual color, typically a shade of deep orange. To prevent unscrupulous individuals from pirating the information, it's usually sealed in an air-proof package. Once the package is opened, an oxidation reaction causes the coating to gradually become darker and more opaque. Once the coating is completely opaque, the DVD can no longer be read by the laser and is useless.I Googled around a bit but I couldn't find too much. I was wondering a couple of things:1.) Is this technology available to consumers yet? If I want to make my own "self-destruct" DVD and seal it up in an air-tight package, can I? This would have a lot of great intellectual property applications -- for instance, I could give a disc of my latest software demos to a company I'm interviewing with, without worrying that they were going to steal my ideas.2.) What prevents someone from, say, polishing off the coating and making the media readable again?3.) Couldn't I stop (or at least significantly slow) the reaction by, say, putting it in the freezer in a ziplock bag?   
  Is there some sort of copy protection? What prevents someone from just copying all of the data off the disc before it "destructs?"   ;  oscinis makes a good point.   ;Quote:Original post by oscinisIs there some sort of copy protection? What prevents someone from just copying all of the data off the disc before it "destructs?"Thats not the point. The point is that most people that receive these DVDs are producers, critics, actors, other indsutry people and so on. These people usually want to see the movie first. If the DVD doesn't self destruct then the chances of someone asking them to borrow the DVD is a lot higher. So its not about eliminating piracy. Its about minimizing it.   ;  In this thread I linked to a company which manufactures these things. Their website does not mention copy protection as one of it's products benefits though. This is understandable since the product is supposed to work like a standard DVD for 8 hours after opening, enough for copying the DVD 10 times over.   ;Quote:Original post by kSquared2.) What prevents someone from, say, polishing off the coating and making the media readable again?DVD's reflective property comes from the reflection of the ink, as it oxidates.. that reflection is lost (therein, actual disappearence of data as an effect).  The data is actually "stored" in this spot, the large chunk of plastic that usually scratches (and can be polished to readable again) is only the buffer to protect the 'ink'.It's common to see people flip a disk upside down to "protect the data" from scratching on the table, but few actually realize the data is on the little wafer on the 'top', not the thick clear part.   ;Quote:Original post by necreiaIt's common to see people flip a disk upside down to "protect the data" from scratching on the table, but few actually realize the data is on the little wafer on the 'top', not the thick clear part.Actually it's safer to place a DVD label-down. A DVD has a large layer of 'plastic' right beneath it's label (link), while a CD does not (link).   ;Quote:Original post by necreiaIt's common to see people flip a disk upside down to "protect the data" from scratching on the table, but few actually realize the data is on the little wafer on the 'top', not the thick clear part.seems that too few people realize the light actually has to pass through this layer without being scattered going in and out.   ;Quote:Original post by kanzlerQuote:Original post by necreiaIt's common to see people flip a disk upside down to "protect the data" from scratching on the table, but few actually realize the data is on the little wafer on the 'top', not the thick clear part.Actually it's safer to place a DVD label-down. A DVD has a large layer of 'plastic' right beneath it's label (link), while a CD does not (link).Very interesting, I wasn't aware that it was that much different than CD's (cool)Quote:Original post by Eelcoseems that too few people realize the light actually has to pass through this layer without being scattered going in and out.What I was getting at (until corrected) was that the data layer cannot be repaired, where the buffer area can be polished.