Digital rights management

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Digital Rights Management (DRM) refers to the laws and technologies which provide intellectual property owners control over the distribution and use of their digital property by defining consumers' rights in its usage. DRM's primary function is to restore control over copying digital media and to restrict access and content use beyond what is granted by copyright law.

Legal Background

The copyright since its formal creation in 1710 by the British Statute of Anne and its inclusion in the first article of the U.S. Constitution has been the main protection scheme for intellectual property rights for creative information goods and services. Copyright law grants exclusive legal ownership of information under specific conditions and terms. Through two major revisions of U.S. copyright law in 1909 and 1976 the range of content and media forms covered by legislation were expanded.

During the pre-digital era, large-scale copying was expensive and usually resulted in degraded content. The development of electronic and digital media transformed the production and distribution of information goods and services. In digital form, the content could be copied perfectly or easily converted to another form or format.

Difficulties of DRM

Legal problems

There is a basic principle of copyright law, called "fair use" in US law. Copyright does not prevent quoting a work in a review or anaylsis, creating a parody of it, and so on. The principle is clear, but border is by no means sharply delineated. Between the black of copyright infringement and the white of perfectly legal fair use, there is a large grey area. This is being narrowed down by various court rulings, but will likely never go away entirely.

That principle greatly complicates the design of DRM systems. Copyright law has exceptions for fair use; how can you design those into DRM software? What do you do about the grey areas? If you ignore fair use, or just misjudge some grey areas, you will infringe on the users' legal rights; what are the market or legal consequences of that?

Technical problems

DRM is attempting a fundamentally difficult task. "Trying to make digital files uncopyable is like trying to make water not wet."

In particular cases, the costs may be quite high. Peter Gutmann, commenting on Microsoft DRM efforts, wrote "The Vista Content Protection specification could very well constitute the longest suicide note in history".

Why is this so difficult? Assume you are a totally legal user of the material protected by DRM, and all the security tests for your music, or your software, are successful. To hear the music, it has to be put into a form the speakers will reproduce. At some point between the DRM-protected recording and the speaker, the signal has to be put into a useful form. Once it is in that form, how does the DRM enforcer prevent it from being copied?

The problem of protecting material on a DVD or other physical storage device are simple when compared to delivering content across the Internet. Think of pay-per-view television. Even in encrypted form, it has to pass through intermediate distribution points on the Internet; the general distribution problem here is part of inter-domain multicast routing (IDMR). How do the legal users get the decryption key for the program for which they have paid, and only for that program? Can anyone along the path from content user to content buyer intercept that key and use it? If so, will the legitimate user still be able to use it? Alternatively, can the stolen key be distributed?