When a virus cripples the dvd player

New copy protection systems bring more uncertainty

The film and music industries are reacting more and more hysterically to the supposed danger of private copying. But copying has been going on ever since tape recorders and video recorders were invented – records and movies were sold anyway. But selling could soon be a thing of the past – for fear of the copy-protection harassment that hdtv, blue-ray-disc and hd-dvd will bring to the plagued customers and overtax them.

Wenn ein auto gestohlen wird, so ist dies fur den besitzer sehr kostspielig, denn gestohlene fahrzeuge werden zwar durchaus haufig wieder gefunden, doch dann in nicht mehr brauchbarem zustand. The damage is compensated by the insurance, but only the current value of the vehicle, which cannot be used to buy a new one. So in any case there is a financial burden and nobody is happy when his car is stolen or rounded up. For the manufacturer, however, it is not a loss, because he can now sell a new car.

Theft protection for cars has therefore only been available as standard for a few years – at the request of the insurance companies. Before that, car locksmiths were often so bad that older vehicles could be unlocked with a bicycle key if necessary – and modern vehicles with a key of the same model in any case. So kam es gar nicht so selten vor, dass man jemanden spatabends nur schnell zur bahn brachte und danach im durcheinander vor dem bahnhof in den falschen wagen einstieg, mitunter sogar losfuhr und den irrtum erst entsetzt bemerkte, weil im radio ein anderer sender eingestellt war. Likewise, the car mix-ups in corporate parking lots like siemens are legend. Laughable in itself, when there have been locksmiths for apartment doors for decades, and the neighborhood kids have no luck with their keys.

A cd or dvd is worth much less than a car: you can get it wrapped in a more or less interesting magazine for less than two euros and even without a magazine from ten euros. The material value is even significantly less than one euro. It is also relatively rarely stolen, not from cars, but rather copied from good friends with the same taste. No one is harmed, because the recipient never bought the corresponding letters himself, but the manufacturer believes that he can sell fewer cds or dvds this way. This also applies to those who give themselves gifts by copying treasures from the collections of richer friends.

Dvd copying – the ultimate crime?

However, the legislation here is much tougher: the copyright act was amended in september 2003 to include paragraphs that make it a criminal offense to circumvent copy protection measures, regardless of the reason for doing so – for example, to be able to play the purchased recording at all. Neither the law nor the technology usually causes gross headaches for commercial pirates, only the normal customer has to deal with cds that don’t work or even install trojans, or dvds brought back from vacation that don’t run in his home dvd player or even make it unusable for local goods by changing a region code. Some dvd drives are even said to burn out due to copy protection reading errors. The customer is now simply stubborn and the industry would like to get rid of him.

While the audio cd was originally an open, standardized medium that was supposed to run without problems on all devices designed for it, the dvd, with its copy protection system css (content scrambling system) and regional code harassment, was already causing more problems. On regular devices, a mixed stock of american and european dvds led to a blockade, and on linux computers, it was not even possible to watch films that had been properly purchased locally: the so-called copy protection proved once again to be a protection against playback.

Although these problems were quickly sorted out and have not yet had a negative effect on dvd sales – on the contrary, some people only took up the cause when region code-free playback formats became available – the film industry was offended and now wants to be sure that the chicanery cannot be avoided with the future high-definition formats blue-ray-disc and hd-dvd, just as with high-definition television hdtv. This leads with the new, super sharp television to the fact that the fool of buyer, who spent already early funfildigige euro sums for its equipment, before a black screen sits and even that, which buys obediently each year a new television set according to the respective standardization, can never be safe whether this plays also really with its remaining components together.

Aacs: the horror comes in stages

With the high-resolution dvd successors blue-ray-disc or hd-dvd, customers are not bullied from the start: for a few years, even screens with analog input were still allowed to show a picture. A reason could be however that it many simply still no computer screens fulfilling the dreams of the fimbranche at the market gives; for tax reasons (import duty: the european union pipe monitor groschen comes) most lcd screens are besides still equipped today with the technically far more complex vga analog input instead of with dvi, and computer screens with the copy protection system hdcp do not exist yet at all at the market. That’s why here the old screens are switched to black only bit by bit. And everything sounds much more harmless than with live tv already protected with full hardness from viewing with old (= more than 1 year) hardware.

But the trick is in the details. Just as cds are now equipped with trojan software that sabotages the purchaser’s computer, blue-ray discs and hd-dvds will also be loaded with things that the customer did not actually order: since experts now ame that every copy protection system will be cracked at some point, they want to simply switch off compromised data carriers and devices or remove the cracked codes from circulation by reloading a corresponding list via the internet.

In dvd players for the living room, which do not have an internet connection, these lists are reloaded via the inserted media: if you buy a new disc and insert it into your device, you feed it with an update before even the first pixel of the film image appears. If he is unlucky, he will find out that his old discs do not run anymore or that the whole device seems to have given up the ghost.

Total loss after update?

If hackers have cracked certain devices or recordings, the honest buyers will pay the price for it. It is still not foreseeable what will happen if the companies quarrel massively and sony for example pushes against matsushita by letting sony bmg burn a list on their discs that turns off all panasonic players. Or if hackers interfere with the communication of computers with the film industry via the internet and simply have all known blue-ray disc or hd-dvd drives switched off.

Certainly, sooner or later there will be discs that you give to your worst enemy, and after inserting them into the device, they will disable it by updating the list of prohibited devices, which simply contains all the devices and keys that have been built so far.

This is called "renewable copy protection", each disc inserted into the player updates the list of prohibited keys and also renews the copy protection software. Here, too, hackers could cause any amount of chaos in a very short time by installing software that triggers unexpected functions or shuts down the device. And of course there doesn’t have to be any "hackers" at all; rather, the manufacturers of anti-virus programs manage to paralyze their systems themselves time and again via their own updates.

Power gone? Broken player!

Edward felten, who has already dealt with the ineffectiveness of css and the illegality of other copy protection systems such as sdmi (between the lines) and has been threatened with criminal prosecution for lectures on these systems, sees in an interview in the latest new scientist in the new copy protection system aacs (advanced access content system) certainly a good technical design, but ames that even this system can be circumvented by professionals. Instead, the normal consumer is burdened with increasingly complicated systems that can fail to work even without intentional sabotage, for example in the event of a power failure shortly after inserting the high-resolution disc, so that the device loses power in the middle of the firmware flashing process. After that it is a case for the warranty as long as it still exists. For older devices, the buyer may pay to have them restored to working order.

The techniques behind aacs are kept secret, unlike older systems, and even the reason why this is the case was not revealed by the industry to new scientist. Seth schoen of the eff therefore predicts that the buyer of such devices will have to deal with two kinds of problems: on the one hand, a mishap such as a power failure at the wrong moment will paralyze the expensive high-resolution dvd player; on the other hand, the film companies will intentionally deprive the device of functions that it still had when purchased and on which the buyer had relied, such as the output of analog signals or, for example, the display of still images.

An alternative system to aacs, self-protecting digital content (spdc), was also originally intended for blue-ray discs and, in the case of corrupted keys, displayed a message that the device owner should call a representative of the movie studio to tell them they had a problem. Here it was amed that pirates won’t have the nerve to call the movie studio if they have problems, but the normal buyer will, which is admittedly a rather optimistic attitude. Aacs, on the other hand, shuts down the device without further discussion. And alternative systems for high-resolution dvds are no less problematic.

Compared with the example at the beginning, this means that the car not only has a factory immobilizer, but after a visit to the car wash, during which the car’s electronics were automatically updated unnoticed, it suddenly no longer starts if the radio is not tuned to the right station, the car was parked in a red light district or there is still gasoline in the tank that is older than four weeks. With a car no one would accept such a thing. Why should you do it with dvd players?