Building a reader for time-restricted books may sound to some like a very stupid thing to do. First, you need to decipher the book using a secret key. Then, you also need to make sure the user cannot do anything with it. You need to keep it from being printed, cut and pasted, etc. Above all, you need to make your program tamper-proof. Because the book reader is the guardian of the book's content, if crackers reverse-engineer it and publish a time-unrestricted reader, your whole business model is lost. What you need to build is a black box.
A black box is a piece of software, hardware, or both that takes encrypted content and optionally a key as its input, and outputs unencrypted data (music, text, video, etc.). A black box must be tamper-proof, to protect the content from being distributed in a non-encrypted form.
When you think about it, there is no obvious way to keep users from turning pages, taking screenshots, and using optical character recognition software, so our black box must be as large and all-encompassing as possible. The ideal black box would plug into your modem, and include a monitor and a pair of speakers, so you could not copy the content in a trivial way.
Imagine some evil cracker manages to break that nice black box and distributes a player that converts encrypted movies into unencrypted MPEG files. Such files will only need to be converted (and paid for) once for all the pirates in the world to publish them. Thanks to the stunning efficiency of Internet-based distribution and peer-to-peer software, the good old Free Software paradigm will turn into "crack once, use everywhere".
Some movie publishers may not be all that happy with this, but the only way for them to stop "terrorist hackers" from violating "intellectual property rights" would be to ban the diffusion of all video content.
Actually, assuming any black box can be broken somewhere, any widespread non-black box device that lets you read the same content as a black box makes that black box useless. For example, the existence of ogg vorbis players makes encrypted music file formats obsolete. In a way, CDs were the ultimate black box; there was no obvious way to get the music from a CD deck to a computer, but since MP3 and CDROM players were created, they have proven completely useless in preventing piracy.
In that regard, Free Software is the ultimate black box killer. The mere existence of Free Software that does what a black box does makes it easy to circumvent the black box and the whole distribution network that feeds it.
Today, it is fairly hard to guarantee that a black box really is tamper-proof. While hardware black boxes require expensive equipment and rare expertise to be broken, few people would really believe in any software-enforced black box. The heroic times of copy-protected games should make that obvious enough to all of us.
Now comes the era of hardware black boxes. Music decoder chips are to be embedded into soundcards, and even CDROM writers are not transparent, since they build the TOC by themselves, making it impossible to do bit-per-bit copies of CDs.
Then there's video. IBM has announced that it is developing a new chip to encrypt the signal that travels between the video card and the monitor. That means that if your video card detects that you replaced your monitor with a video-recording device, it will automatically downgrade the image quality. What this effectively does is put the monitor inside the black box.
Another trend is the development of electronic book readers. These notepad-like electronic devices have a nice LCD panel, a network connection, and a touchscreen. They have no keyboard; their only job is to let you read electronic books in a convenient manner. The side effect of their high level of integration is that they may become very opaque. Who wants to hack on a piece of hardware that doesn't have a keyboard, let alone a compiler?
The consequence of all of this is that in order to keep stupid teenagers from shuffling around tons of books, movies, and MP3s they wouldn't have paid for anyway, the industry will be pushing for a ban of technological means for diffusion of any content. No writing your own DVD-Video disks, no publishing self-authored audio recordings (without expensive "professional" hardware), and security through obscurity for all.
The development of black boxes seems to be a very dark thing for the worlds of Free Software, free speech, and interoperability. This is not new, as Free Software and open standards have been opposed to secrecy since their dawn a few decades ago.
However, if the business model of time-restricted books develops, we will be surrounded by content that is conceptually incompatible with openness. Yet another industry will have a strong incentive to oppose interoperability.
Many may agree that lobbying is one of the worst things that have happened to Free Software and freedom of speech because it short-circuits democratic control; large companies have used it to hinder the public interest for the sake of short-term profit. The MPAA, the RIAA, software patent advocates, nuclear power advocates, and many others have shown how little they cared for our rights, whether on American soil or abroad.
I say the last thing we want is yet another lobby on our back. If technologies that require black boxes for text diffusion become mainstream, yet another industry will have a strong incentive to arrange for these black boxes to become ubiquitous. This will mean sacrificing freedom of speech and outlawing Free software. That is not quite what I want for my children.
If we don't want to get into the world described by Stallman's "The Right to Read", time-limited books are the last thing we need. We should boycott them and spread the word about the danger they represent. We should also strive to offer valuable content freely, either as free content or under such business models as the Street Performers Protocol. By relying only on Free Software and freely available content, and by refusing to use pirated music and programs, we will be proving to the world that it can be done. I encourage you to seek and produce freely available content. Cheap is not enough when our Freedom is at stake.