Digital TV flags 'will not stop piracy'

[Gregg Lengling]

13:28 06 November 03
 
NewScientist.com news service
 
The US "broadcast flag" system aiming to prevent online piracy of digital TV programming will not work, say computer experts.

On Tuesday, the US Federal Communications Commission (FCC) announced that all hardware digital TV receivers built after 2005 must be capable of responding to a copyright protection mechanism embedded in digital broadcasts.

But computer scientists say that injecting a string of bits called a broadcast flag into the signal will not stop widespread redistribution of TV shows on the internet.

"Is this going to do what the movie industry is looking for? No. This will not have the desired effect," says Drew Dean of the Computer Science Laboratory at the SRI Institute in Menlo Park, California.

The Moving Picture Association of America (MPAA) fears that the advent of digital TV could boost the number of movies being freely and illegally shared online, and had demanded the FCC respond to the threat.

"By taking preventative action, we can forestall the development of a problem in the future similar to that currently being experienced by the music industry," states the FCC report. The new regulations will apply to TVs specifically made to receive digital signals, as well as add-ons for PCs and ordinary TVs.

But many computer experts agree that the distribution of digital information is unstoppable. "These technologies will get defeated - there are always work-arounds," says Dan Wallach, a computer scientist at Rice University in Texas.


Data restrictions


The broadcast flag is a short string of data that sits within the stream of bits that make up the signal broadcast by the TV station. The stream delivers a compressed version of the TV show and must be decompressed by a receiver to be viewed.

The new hardware will read the broadcast flag during decompression and then impose restrictions on the data. The FCC has not yet issued specifications, but a likely scenario is that when a device detects a broadcast flag, it will not be capable of uploading the file to the internet.

The most obvious problem is that this broadcast flag will be invisible to all existing devices and any made before 2005. So after 2005 people could still use older devices to record digital content and then distribute it.

Another problem is that the rules only apply to hardware. But software already exists that decompresses radio signals and converts them into music. This software could be easily adapted to receive TV signals on a general purpose computer and would thereby dodge the new FCC laws.


It only takes one
Edward Felten, a computer scientist at Princeton University, notes: "Once even one skilled person has extracted the content, it can be made available to everybody on the internet."

But he says that people are unlikely to make a habit of sharing movies online as they do music files, because more bandwidth and storage space are required for this than most ordinary consumers can afford.

"These limitations are much more important in practice, and the broadcast flag does not affect them one way or the other," he told New Scientist.

But even if the broadcast flag is unlikely to be effective, computer experts say, they are not necessarily harmless. "Criminals will not be dissuaded by something as simple as a broadcast flag," says Wallach, but ordinary consumers who legitimately want to record a show for a neighbour or a friend might be.