DAT, CD, and DVD copy prevention
There have been some very interesting developments in the CD and DVD industries where they have come up with ways of putting information on those devices that makes it very difficult to copy them successfully. But, as with many things, making something difficult to copy successfully and achieving copy prevention are different things.
To take a practical example, in the CD/DVD industry there was an attempt to prevent people from being able to play information if the hardware they were using did not originate in the same geographic region as the CD/DVD was encoded for. This required controls to be built into hardware devices and also into software. So those industries were exposed to the willingness of many manufacturers to implement controls that met their copy prevention controls.
But things didn’t always work out how they planned.
Digital audio tape (DAT) was the first real attempt to introduce very strong controls to prevent copying. These were so strong that users could not guarantee to be able to copy their own recordings, never mind recordings from other sources. And solely because of the copy prevention system, DAT never became a commercial success in the consumer marketplace, and now lives, if at all, only in commercial studios. And the manufacturers lost significant sums of money as a result.
Regional controls on CDs and DVDs was an attempt to introduce use controls to ensure that you could only use a work in the region in which it was sold. This was not copy prevention per se, but it limited the market that copies could be sold into, trying to make copying less commercially valuable to the copier. It failed because the manufacturer’s of players found that consumers would not accept this restriction because consumers took the view that what they had purchased fairly they had a right to view, and that the player manufacturer did not have the right to make artificial distinctions. One result of this was a French law requiring player manufacturers to make machines that would play all formats regardless of security settings! The end result has been that manufacturers have made multi-region players available, thus achieving their (and the consumers who are their customers) market demands and the IPR owners found that they had to give way or watch their own markets fall apart because they did not have a strong enough economic case with the consumers.
Document copy prevention
Preventing people from making usable copies of documents is critical to achieving effective document security. Copy prevention may be achieved in a number of ways. For example:
- In Microsoft Azure RMS you have a complex collaboration infrastructure using cryptographic controls allowing protected documents to be modified by authorized users and circulated within defined groups of users. It also allows for ‘transitive controls’ where a recipient is able to grant new rights to users, or even allow them to redefine previous controls in their own environment(s). This has tight integration with Microsoft Office applications and requires careful configuration.
- In PDF protection systems using passwords (based upon the Adobe standard) copying is not prevented, but instead focuses on the print quality available and the ability to edit the document. If a user must enter a password to open a PDF document they can pass it on to anyone they choose rendering the copy prevention useless.
- More sophisticated PDF DRM systems such as that implemented by Locklizard, copying is not forbidden, but using a copy is licensed through cryptographic controls – unless a user has been authorized they cannot view it. Users are not allowed to edit protected documents nor can they grant other users rights to documents. Users do not have Save or Save As functionality available. Document printing is controlled and watermarking may be added to viewed pages and printed copies to resist photocopying or photography as a means of copying. Finally, in a DRM based system license checking and document use dates may be used to prevent access to documents and thus prevent document copying.
Effective copy prevention controls
So copy prevention controls, if they are to be effective and accepted, must not seek to introduce controls that effectively prevent legitimate users from using the rights that they have purchased. But one has to be careful to look into what are the commercial and social factors that one must take into account, and understand that these may be different for different specific types of IPR.
An alternative way of achieving copy prevention is not to prevent it at all, but to make the copy of no value if the user is not licensed to use it. This might sound a bit esoteric, but if the person who has purchased something is able to copy it freely, say for backup purposes, and may use any of their copies at any time, but other people are not able to use those copies, then you have achieved unlicensed copy prevention, which might actually be the real objective.