December 21, 2024

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Archives for 2004

DVD Replacement Still Insecure

December 1, 2004 by

There’s a budding format war in the movie industry, over which video medium will replace the DVD. The candidates are called HD-DVD and Blu-Ray. For some reason, HD-DVD advocates are claiming that their format can better resist unauthorized copying.

As far as I can tell, there is essentially zero evidence to support this claim. In fact, as James Grimmelmann neatly argues, there is really no reason to think that either of these technologies will be effective at stopping peer-to-peer sharing. Here’s James:

Already I’m confused. What will changing the physical format of non-interactive discs do to “stem rampant piracy?” The new format will have to be readable by some class of devices. It will have to be writable by some other class of devices. The level of “rampant piracy” of DVDs has never been a function of the weakness of CSS; the level of rampant piracy of HD-DVDs won’t be a function of the weakness or strength of the encryption algorithm.

Making HD-DVDs harder to copy than DVDs would take one of three things:

  • It’s not practical to get at the bits except to throw them immediately up on the screen. But this would mean no HD-DVD readers or writers for computers – and the equipment vendors have been saying that HD-DVD drives for computers are one of their major markets.
  • The discs (or disc substitutes) are in some way “smart” and do a two-way handshake with the computer so that you can’t, as with CSS, extract a key once and use it forever. But that would raise the manufacturing costs immensely, which defeats one of the major design goals.
  • The discs are individuated and the readers have to check in with home base to be authorized to read a particular disc and get its particular key. But this would require every HD-DVD device to have an Internet connection.

Actually, they would probably have to do all three of these things, and more, to make any dent in P2P copying. The system will be attacked at its weakest point. If they fix only one or two of their many problems, the remaining one(s) will still be fatal.

Reporters and industry analysts are still surprisingly gullible about DRM vendors’ claims. What we have here is essentially a replay of the early security claims about DVDs, which turned out to be spectacularly wrong.

Perhaps people are drawing the wrong lesson from the failure of DVDs to prevent copying. It’s true that the CSS encryption system used on DVDs turned out to be laughably weak. But, as James notes, that wasn’t even the biggest problem in the DVD anti-copying strategy. Indeed, if you replaced CSS with an utterly unbreakable encryption system, DVDs would still have been easy to copy, by capturing the data after it was decrypted, or by reverse-engineering a player to learn the secret decryption key.

Here’s a good rule of thumb for reporters and analysts: If somebody claims to have solved a security problem that nobody has ever solved in practice before, don’t believe them unless they present independently verified evidence to support their claim.

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Lycos Attacks Alleged Spammers

November 30, 2004 by

Lycos Europe is distributing a screen saver that launches denial of service attacks on the websites of suspected spammers, according to a Craig Morris story at Heise Online. The screen saver sends dummy requests to the servers in order to slow them down. It even displays information to the user about the current attack target.

This is a serious lapse of judgment by Lycos. For one thing, this kind of vigilante attack erodes the line between the good guys and the bad guys. Spammers are bad because they use resources and keep people from getting to the messages they want to read. If you respond by wasting resources and keeping people from getting to the websites they want to read, it’s hard to see what separates you from the spammers.

This kind of attack can be misdirected at innocent parties. The article says that Lycos is attacking sites on the SpamCop blocklist. That doesn’t fill me with confidence – this site has been on the SpamCop blocklist at least once, despite having nothing at all to do with spam. (The cause was an erroneous complaint, coupled with a hair-trigger policy by SpamCop.)

We also know that spammers have a history of trying to frame innocent people as being sources of spam. A basic method for doing this is common enough to have a name: “Joe job”. Attacking the apparent sources of spam just makes such misdirection more effective.

And finally, there’s the question of whether this is legal. The Heise Online article reaches no conclusion about its legality in Germany, and I don’t know enough to say whether it’s legal in the U.S. Lycos argues that it’s not really a denial of service attack because they’re careful not to block access to the sites completely. But they do brag about raising the sites’ costs and degrading the experience of the sites’ users. That’s enough to make it a denial of service attack in my book.

This idea – attacking spammer sites – is one that surfaces occasionally, but usually cooler heads prevail. It’s a real surprise to see a prominent company putting it into action.

[Link via TechDirt. And did I mention that TechDirt is a great source of interesting technology news?]

UPDATE (Dec. 6): Lycos has now withdrawn this program, declaring implausibly that it has succeeded and so is no longer needed.

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Radio Passports: Bad Idea

November 29, 2004 by

An AP story nicely summarizes the controversy over the U.S. government’s plan to add RFID chips to U.S. passports, starting in 2005.

The chips will allow the passport holder’s name, date of birth, passport issuance information, and photograph to be read by radio. Opponents claim that the information will be readable at distances up to thirty feet (about nine meters). This raises privacy concerns about government monitoring, for example of attendance at political rallies, and about private monitoring, especially overseas.

I would certainly feel less safe in certain places if I knew that anybody there could remotely identify me as a U.S. citizen. I would feel even less safe knowing that anybody could get my name and look me up in a database or Google me.

A U.S. government representative says that there is “little risk” to privacy “since we plan to store only currently collected data with a facial image.” In other words, they’re going to take information currently available only to people to whom I hand my passport, plus some extra information, and make it available to everybody who comes near me. Gee, that makes me feel much better.

There is some discussion of encrypting the information, or requiring the passport holder to enter a PIN number to unlock the information. Either of these is some help, but unless the system is designed very carefully, it could still allow dangerous leakage of information.

What I don’t understand is why passports should ever be readable at a distance. Passports should reveal their information only to people or devices who can make physical contact to the inside of the passport. Certainly that’s enough for the immigration agent at the airport, or for any official who asks to inspect the passport. If the officials are doing their jobs, they’ll want to see the physical passport and hold it in their hands anyway.

Oddly, the government’s response to concerns about remote passport reading is to try to limit when the passport can be read remotely. They propose storing the passport in a conductive plastic bag that blocks radio signals, or building a conductive screen into the passport’s covers so that it can be read remotely only when the passport is opened. Either approach adds unnecessary risk – the passport might be read by somebody else when it’s opened.

The right solution, which opponents should advocate, is to remove radio tags from passports altogether, and replace them with contact-readable electronic information.

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Keylogging is Not Wiretapping, Judge Says

November 24, 2004 by

A Federal judge in California recently dismissed wiretapping charges against a man who installed a “keylogger” device on the cable between a woman’s keyboard and her computer. I was planning to write a reaction to the decision, but Orin Kerr seems to have nailed it already.

This strikes me as yet another example of a legal analyst (the judge, in this case) focusing on one layer of a system and not seeing the big picture. By fixating on the fact that the interception happened at a place not directly connected to the Internet, the judge lost sight of the fact that many of the keystrokes being intercepted were being transmitted over the Net.

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EFF Names Advisory Board

November 23, 2004 by

The Electronic Frontier Foundation has named its first advisory board. I’m on it, along with Michael Froomkin, Paul Grewal, Jim Griffin, David Hayes, Mitch Kapor, Mark Lemley, Eben Moglen, Deirdre Mulligan, Michael Page, Michael Traynor, and Jim Tyre.

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