Well how exactly does one prevent data from being stolen once it has been unlocked? I pay my 2X to view the picture anonymously and now I copy it save it and distribute it worldwide. I fail to see how any encryption/watermark scheme can prevent me from doing so.
The short answer: you can't prevent theft of copyrighted data if the user has physical control of the computer the data resides on. The long answer: depending on the OS and the hardware, you can make it difficult enough that it is not worth the effort for low-value data. As a veteran of the copy-protection wars (so, am I one of just 3 people on this list approaching/into middle age? (hi Tim and William :))), I know that it is impossible to protect unencrypted data if the user has physical control of the system. Unfortunately, in order to use the data, you have to decrypt the darn stuff!! Especially with the OSes commonly in use on PCs (DOS, Win3.1, Win95, MacOS), there is very little memory protection going on, so snarfing the data can be done entirely through software by a determined cracker -- there is no need to resort to hardware hacks. Technological protection against theft of intellectual property is like the search for the Philosopher's Stone during the Middle Ages -- many are seduced by the promise, but it is a promise that cannot be kept by personal computers. If the display device is/incorporates a general-purpose computer that can be physically accessed, then the data in the display device is subject to compromise. The very flexibility and accessibility of a general-purpose computing device is its undoing when it comes to protected unencrypted data -- and data has to be unencrypted to be used. ========================================================== Mark Leighton Fisher Thomson Consumer Electronics fisherm@indy.tce.com Indianapolis, IN "Their walls are built of cannon balls, their motto is 'Don't Tread on Me'"