The "Oyster card" used on the London Tube was at issue in the Dutch case, and a similar fare card used on the Boston "T" was the center of the U.S. case. The Dutch court got it right, and the American court, in Boston, got it wrong from the start -- despite facing an open-and-shut case of First Amendment prior restraint.

The U.S. court has since seen the error of its ways -- but the damage is done. The MIT security researchers who were prepared to discuss their Boston findings at the DefCon security conference were prevented from giving their talk.

The ethics of full disclosure are intimately familiar to those of us in the computer-security field. Before full disclosure became the norm, researchers would quietly disclose vulnerabilities to the vendors -- who would routinely ignore them. Sometimes vendors would even threaten researchers with legal action if they disclosed the vulnerabilities.

Later on, researchers started disclosing the existence of a vulnerability but not the details. Vendors responded by denying the security holes' existence, or calling them just theoretical. It wasn't until full disclosure became the norm that vendors began consistently fixing vulnerabilities quickly. Now that vendors routinely patch vulnerabilities, researchers generally give them advance notice to allow them to patch their systems before the vulnerability is published. But even with this "responsible disclosure" protocol, it's the threat of disclosure that motivates them to patch their systems. Full disclosure is the mechanism (.pdf) by which computer security improves.

Outside of computer security, secrecy is much more the norm. Some security communities, like locksmiths, behave much like medieval guilds, divulging the secrets of their profession only to those within it. These communities hate open research, and have responded with surprising vitriol to researchers who have found serious vulnerabilities in bicycle locks, combination safes (.pdf), master-key systems and many other security devices.

Researchers have received a similar reaction from other communities more used to secrecy than openness. Researchers -- sometimes young students -- who discovered and published flaws in copyright-protection schemes, voting-machine security and now wireless access cards have all suffered recriminations and sometimes lawsuits for not keeping the vulnerabilities secret. When Christopher Soghoian created a website allowing people to print fake airline boarding passes, he got several unpleasant visits from the FBI.

This preference for secrecy comes from confusing a vulnerability with information about that vulnerability. Using secrecy as a security measure is fundamentally fragile. It assumes that the bad guys don't do their own security research. It assumes that no one else will find the same vulnerability. It assumes that information won't leak out even if the research results are suppressed. These assumptions are all incorrect.

The problem isn't the researchers; it's the products themselves. Companies will only design security as good as what their customers know to ask for. Full disclosure helps customers evaluate the security of the products they buy, and educates them in how to ask for better security. The Dutch court got it exactly right when it wrote: "Damage to NXP is not the result of the publication of the article but of the production and sale of a chip that appears to have shortcomings."

In a world of forced secrecy, vendors make inflated claims about their products, vulnerabilities don't get fixed, and customers are no wiser. Security research is stifled, and security technology doesn't improve. The only beneficiaries are the bad guys.

If you'll forgive the analogy, the ethics of full disclosure parallel the ethics of not paying kidnapping ransoms. We all know why we don't pay kidnappers: It encourages more kidnappings. Yet in every kidnapping case, there's someone -- a spouse, a parent, an employer -- with a good reason why, in this one case, we should make an exception.

The reason we want researchers to publish vulnerabilities is because that's how security improves. But in every case there's someone -- the Massachusetts Bay Transit Authority, the locksmiths, an election machine manufacturer -- who argues that, in this one case, we should make an exception.

We shouldn't. The benefits of responsibly publishing attacks greatly outweigh the potential harm. Disclosure encourages companies to build security properly rather than relying on shoddy design and secrecy, and discourages them from promising security based on their ability to threaten researchers. It's how we learn about security, and how we improve future security.

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Bruce Schneier is Chief Security Technology Officer of BT Global Services and author of Beyond Fear: Thinking Sensibly About Security in an Uncertain World. You can read more of his writings on his website.

We write to express our firm belief that research on security vulnerabilities, and the sensible publication of the results of the research, are critical for scientific advancement, public safety and a robust market for secure technologies. Generally speaking, the norm in our field is that researchers take reasonable steps to protect the individuals using the systems studied. We understand that the student researchers took such steps with regard to their research, notably by planning not to present a critical element of a flaw they found. They did this so that their audience would be unable to exploit the security flaws they uncovered. . . .

The restraining order at issue in this case also fosters a dangerous information imbalance. In this case, for example, it allows the vendors of the technology and the MBTA to claim greater efficacy and security than their products warrant, then use the law to silence those who would reveal the technologies’ flaws. In this case, the law gives the public a false sense of security, achieved through law, not technical effectiveness. Preventing researchers from discussing a technology’s vulnerabilities does not make them go away - in fact, it may exacerbate them as more people and institutions use and come to rely upon the illusory protection. Yet the commercial purveyors of such technologies often do not want truthful discussions of their products’ flaws, and will likely withhold the prior approval or deny researchers access for testing if the law supports that effort. . . .

Yet at the same time that researchers need to act responsibly, vendors should not be granted complete control of the publication of such information, as it appears MBTA sought here. As noted above, vendors and users of such technologies often have an incentive to hide the flaws in the system rather than come clean with the public and take the steps necessary to remedy them. Thus, while researchers often refrain from publishing the technical details necessary to exploit the flaw, a legal ban on discussion of security flaws, such as that contained in the temporary restraining order, is especially troubling.

It will be interesting to see what arguments the MBTA uses to keep the students from speaking on a topic where all the important vulnerability information seems to have already disclosed. Sure the students haven’t presented a cookbook exploit tool but they have also stated they have no intention of doing so.

Perhaps the court will investigate what the MBTA’s and their technology vendors response has been to the MiFare card vulnerabilities that were disclosed responsibly. If there has been no vigorous response to responsibly disclosed vulnerabilities of many months ago how can they say with a straight face that are truly responding to new security information and just need more time.

We write to express our firm belief that research on security vulnerabilities, and the sensible publication of the results of the research, are critical for scientific advancement, public safety and a robust market for secure technologies. Generally speaking, the norm in our field is that researchers take reasonable steps to protect the individuals using the systems studied. We understand that the student researchers took such steps with regard to their research, notably by planning not to present a critical element of a flaw they found. They did this so that their audience would be unable to exploit the security flaws they uncovered. . . .

The restraining order at issue in this case also fosters a dangerous information imbalance. In this case, for example, it allows the vendors of the technology and the MBTA to claim greater efficacy and security than their products warrant, then use the law to silence those who would reveal the technologies’ flaws. In this case, the law gives the public a false sense of security, achieved through law, not technical effectiveness. Preventing researchers from discussing a technology’s vulnerabilities does not make them go away - in fact, it may exacerbate them as more people and institutions use and come to rely upon the illusory protection. Yet the commercial purveyors of such technologies often do not want truthful discussions of their products’ flaws, and will likely withhold the prior approval or deny researchers access for testing if the law supports that effort. . . .

Yet at the same time that researchers need to act responsibly, vendors should not be granted complete control of the publication of such information, as it appears MBTA sought here. As noted above, vendors and users of such technologies often have an incentive to hide the flaws in the system rather than come clean with the public and take the steps necessary to remedy them. Thus, while researchers often refrain from publishing the technical details necessary to exploit the flaw, a legal ban on discussion of security flaws, such as that contained in the temporary restraining order, is especially troubling.

It will be interesting to see what arguments the MBTA uses to keep the students from speaking on a topic where all the important vulnerability information seems to have already disclosed. Sure the students haven’t presented a cookbook exploit tool but they have also stated they have no intention of doing so.

Perhaps the court will investigate what the MBTA’s and their technology vendors response has been to the MiFare card vulnerabilities that were disclosed responsibly. If there has been no vigorous response to responsibly disclosed vulnerabilities of many months ago how can they say with a straight face that are truly responding to new security information and just need more time.

It's basically what you would expect: Appoint a national cyber security advisor, invest in math and science education, establish standards for critical infrastructure, spend money on enforcement, establish national standards for securing personal data and data-breach disclosure, and work with industry and academia to develop a bunch of needed technologies.

I could comment on the plan, but with security the devil is always in the details -- and, of course, at this point there are few details. But since he brought up the topic -- McCain supposedly is "working on the issues" as well -- I have three pieces of policy advice for the next president, whoever he is. They're too detailed for campaign speeches or even position papers, but they're essential for improving information security in our society. Actually, they apply to national security in general. And they're things only government can do.

One, use your immense buying power to improve the security of commercial products and services. One property of technological products is that most of the cost is in the development of the product rather than the production. Think software: The first copy costs millions, but the second copy is free.

You have to secure your own government networks, military and civilian. You have to buy computers for all your government employees. Consolidate those contracts, and start putting explicit security requirements into the RFPs. You have the buying power to get your vendors to make serious security improvements in the products and services they sell to the government, and then we all benefit because they'll include those improvements in the same products and services they sell to the rest of us. We're all safer if information technology is more secure, even though the bad guys can use it, too.

Two, legislate results and not methodologies. There are a lot of areas in security where you need to pass laws, where the security externalities are such that the market fails to provide adequate security. For example, software companies who sell insecure products are exploiting an externality just as much as chemical plants that dump waste into the river. But a bad law is worse than no law. A law requiring companies to secure personal data is good; a law specifying what technologies they should use to do so is not. Mandating software liabilities for software failures is good, detailing how is not. Legislate for the results you want and implement the appropriate penalties; let the market figure out how -- that's what markets are good at.

Three, broadly invest in research. Basic research is risky; it doesn't always pay off. That's why companies have stopped funding it. Bell Labs is gone because nobody could afford it after the AT&T breakup, but the root cause was a desire for higher efficiency and short-term profitability -- not unreasonable in an unregulated business. Government research can be used to balance that by funding long-term research.

Spread those research dollars wide. Lately, most research money has been redirected through DARPA to near-term military-related projects; that's not good. Keep the earmark-happy Congress from dictating (.pdf) how the money is spent. Let the NSF, NIH and other funding agencies decide how to spend the money and don't try to micromanage. Give the national laboratories lots of freedom, too. Yes, some research will sound silly to a layman. But you can't predict what will be useful for what, and if funding is really peer-reviewed, the average results will be much better. Compared to corporate tax breaks and other subsidies, this is chump change.

If our research capability is to remain vibrant, we need more science and math students with decent elementary and high school preparation. The declining interest is partly from the perception that scientists don't get rich like lawyers and dentists and stockbrokers, but also because science isn't valued in a country full of creationists. One way the president can help is by trusting scientific advisers and not overruling them for political reasons.

Oh, and get rid of those post-9/11 restrictions on student visas that are causing (.pdf) so many top students to do their graduate work in Canada, Europe and Asia instead of in the United States. Those restrictions will hurt us (.pdf) immensely in the long run.

Those are the three big ones; the rest is in the details. And it's the details that matter. There are lots of serious issues that you're going to have to tackle: data privacy, data sharing, data mining, government eavesdropping, government databases, use of Social Security numbers as identifiers, and so on. It's not enough to get the broad policy goals right. You can have good intentions and enact a good law, and have the whole thing completely gutted by two sentences sneaked in during rulemaking by some lobbyist.

Security is both subtle and complex, and -- unfortunately -- it doesn't readily lend itself to normal legislative processes. You're used to finding consensus, but security by consensus rarely works. On the internet, security standards are much worse when they're developed by a consensus body, and much better when someone just does them. This doesn't always work -- a lot of crap security has come from companies that have "just done it" -- but nothing but mediocre standards come from consensus bodies. The point is that you won't get good security without pissing someone off: The information broker industry, the voting machine industry, the telcos. The normal legislative process makes it hard to get security right, which is why I don't have much optimism about what you can get done.

And if you're going to appoint a cyber security czar, you have to give him actual budgetary authority -- otherwise he won't be able to get anything done, either.

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Bruce Schneier is chief security technology officer of BT, and author of Beyond Fear: Thinking Sensibly About Security in an Uncertain World.

10:00-11:00 FX, Developments in Cisco IOS Forensics.

11:15-12:30 Oliver Friedrichs, Threats to the 2008 Presidential Election (and more).

13:45-15:00 Option 1: Scott Stender, Concurrency Attacks in Web Applications. Option 2: Travis Goodspeed, Side-channel Timing Attacks on MSP430 Microcontroller Firmware.

15:15-16:30 Option 1: Alexander Sotirov and Mark Dowd, How To Impress Girls With Browser Memory Protection Bypasses. Option 2: Karsten Nohl, Mifare - Little Security, Despite Obscurity. This is one of the toughest time slots as you also have McFeters/Carter/Heasman and Grossman/Evans in the lineup. Choices, choices.

16:45-18:00 Option 1: Bruce Dang, Methods for Understanding Targeted Attacks with Office Documents. Option 2: Christopher Tarnovsky, Inducing Momentary Faults Within Secure Smartcards/Microcontrollers.

Lots of intriguing hardware talks on Day 2. A lot of it is probably over my head and my first options are more applicable to my day job. There might have to be some room hopping.

I fly out to Vegas tonight — see you all there!

10:00-11:00 FX, Developments in Cisco IOS Forensics.

11:15-12:30 Oliver Friedrichs, Threats to the 2008 Presidential Election (and more).

13:45-15:00 Option 1: Scott Stender, Concurrency Attacks in Web Applications. Option 2: Travis Goodspeed, Side-channel Timing Attacks on MSP430 Microcontroller Firmware.

15:15-16:30 Option 1: Alexander Sotirov and Mark Dowd, How To Impress Girls With Browser Memory Protection Bypasses. Option 2: Karsten Nohl, Mifare - Little Security, Despite Obscurity. This is one of the toughest time slots as you also have McFeters/Carter/Heasman and Grossman/Evans in the lineup. Choices, choices.

16:45-18:00 Option 1: Bruce Dang, Methods for Understanding Targeted Attacks with Office Documents. Option 2: Christopher Tarnovsky, Inducing Momentary Faults Within Secure Smartcards/Microcontrollers.

Lots of intriguing hardware talks on Day 2. A lot of it is probably over my head and my first options are more applicable to my day job. There might have to be some room hopping.

I fly out to Vegas tonight — see you all there!

Well-known author and expert on security, Bruce Schneier, born in 1963, maintains "Terrorists can only take my life. Only my government can take my freedom."

I don't think I've ever said that. It certainly doesn't sound like something I would say. It's not in any of my books. It's not in any of the essays I've written.

So I Googled the quote. Here it is being used as a sig in December 2001, without attribution. The real source must be at least as old as that. The immediate source might be this blog. Possibly, it might come from this comment to my blog, reworded and attributed to me:

Surely the man who trades freedom for security theatre deserves both freedom and security less than the first man!

I like that quote, "we must remember that we have more power than our enemies to worsen our fate". Terrorists can, at most, take away my life. They can never take away my freedom. Only my government has the power to do that.

Anyone have any better theories?

The details of the vulnerability aren't important, but basically it's a form of DNS cache poisoning. The DNS system is what translates domain names people understand, like www.schneier.com, to IP addresses computers understand: 204.11.246.1. There is a whole family of vulnerabilities where the DNS system on your computer is fooled into thinking that the IP address for www.badsite.com is really the IP address for www.goodsite.com -- there's no way for you to tell the difference -- and that allows the criminals at www.badsite.com to trick you into doing all sorts of things, like giving up your bank account details. Kaminsky discovered a particularly nasty variant of this cache-poisoning attack.

Here's the way the timeline was supposed to work: Kaminsky discovered the vulnerability about six months ago, and quietly worked with vendors to patch it. (There's a fairly straightforward fix, although the implementation nuances are complicated.) Of course, this meant describing the vulnerability to them; why would companies like Microsoft and Cisco believe him otherwise? On July 8, he held a press conference to announce the vulnerability -- but not the details -- and reveal that a patch was available from a long list of vendors. We would all have a month to patch, and Kaminsky would release details of the vulnerability at the BlackHat conference early next month.

Of course, the details leaked. How isn't important; it could have leaked a zillion different ways. Too many people knew about it for it to remain secret. Others who knew the general idea were too smart not to speculate on the details. I'm kind of amazed the details remained secret for this long; undoubtedly it had leaked into the underground community before the public leak two days ago. So now everyone who back-burnered the problem is rushing to patch, while the hacker community is racing to produce working exploits.

What's the moral here? It's easy to condemn Kaminsky: If he had shut up about the problem, we wouldn't be in this mess. But that's just wrong. Kaminsky found the vulnerability by accident. There's no reason to believe he was the first one to find it, and it's ridiculous to believe he would be the last. Don't shoot the messenger. The problem is with the DNS protocol; it's insecure.

The real lesson is that the patch treadmill doesn't work, and it hasn't for years. This cycle of finding security holes and rushing to patch them before the bad guys exploit those vulnerabilities is expensive, inefficient and incomplete. We need to design security into our systems right from the beginning. We need assurance. We need security engineers involved in system design. This process won't prevent every vulnerability, but it's much more secure -- and cheaper -- than the patch treadmill we're all on now.

What a security engineer brings to the problem is a particular mindset. He thinks about systems from a security perspective. It's not that he discovers all possible attacks before the bad guys do; it's more that he anticipates potential types of attacks, and defends against them even if he doesn't know their details. I see this all the time in good cryptographic designs. It's over-engineering based on intuition, but if the security engineer has good intuition, it generally works.

Kaminsky's vulnerability is a perfect example of this. Years ago, cryptographer Daniel J. Bernstein looked at DNS security and decided that Source Port Randomization was a smart design choice. That's exactly the work-around being rolled out now following Kaminsky's discovery. Bernstein didn't discover Kaminsky's attack; instead, he saw a general class of attacks and realized that this enhancement could protect against them. Consequently, the DNS program he wrote in 2000, djbdns, doesn't need to be patched; it's already immune to Kaminsky's attack.

That's what a good design looks like. It's not just secure against known attacks; it's also secure against unknown attacks. We need more of this, not just on the internet but in voting machines, ID cards, transportation payment cards ... everywhere. Stop assuming that systems are secure unless demonstrated insecure; start assuming that systems are insecure unless designed securely.

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Bruce Schneier is chief security technology officer of BT, and author of Beyond Fear: Thinking Sensibly About Security in an Uncertain World.

In a man-in-the-middle attack, the attacker inserts himself between two communicating parties. Both believe they're talking to each other, and the attacker can delete or modify the communications at will. The Wall Street Journal reported how this gambit played out in Colombia.

This ploy worked because Cesar and his guerrilla bosses didn't know each other well. They didn't recognize each others' voices, and didn't have a friendship or shared history that could have tipped them off about the ruse. Man-in-the-middle is defeated by context, and the FARC guerillas didn't have any.

And that's why man-in-the-middle, abbreviated MITM in the computer security community, is such a problem online: Internet communication is often stripped of any context. There's no way to recognize someone's face. There's no way to recognize someone's voice. When you receive an e-mail purporting to come from a person or organization, you have no idea who actually sent it. When you visit a website, you have no idea if you're really visiting that website. We all like to pretend that we know who we're communicating with -- and for the most part, of course, there isn't any attacker inserting himself into our communications -- but in reality, we don't. And there are lots of hacker tools that exploit this unjustified trust, and implement MITM attacks.

Even with context, it's still possible for MITM to fool both sides -- because electronic communications are often intermittent. Imagine that one of the FARC guerillas became suspicious about who he was talking to. So he asks a question about their shared history as a test: "What did we have for dinner that time last year?" or something like that. On the telephone, the attacker wouldn't be able to answer quickly, so his ruse would be discovered. But e-mail conversation isn't synchronous. The attacker could simply pass that question through to the other end of the communications, and when he got the answer back, he would be able to reply.

This is the way MITM attacks work against web-based financial systems. A bank demands authentication from the user: a password, a one-time code from a token or whatever. The attacker sitting in the middle receives the request from the bank and passes it to the user. The user responds to the attacker, who passes that response to the bank. Now the bank assumes it is talking to the legitimate user, and the attacker is free to send transactions directly to the bank. This kind of attack completely bypasses any two-factor authentication mechanisms, and is becoming a more popular identity theft tactic.

There are cryptographic solutions to MITM attacks, and there are secure web protocols that implement them. Many of them require shared secrets, though, making them only useful in situations where people already know and trust each other.

The NSA-designed STU-III and STE secure telephones solve the MITM problem by embedding the identity of each phone together with its key. (The NSA creates all keys and is trusted by everyone, so this works.) When two phones talk to each other securely, they exchange keys and display the other phone's identity on a screen. Because the phone is in a secure location, the user now knows who he is talking to, and if the phone displays another organization -- as it would if there were a MITM attack in progress -- he should hang up.

Zfone, a secure VoIP system, protects against MITM attacks with a short authentication string. After two Zfone terminals exchange keys, both computers display a four-character string. The users are supposed to manually verify that both strings are the same -- "my screen says 5C19; what does yours say?" -- to ensure that the phones are communicating directly with each other and not with an MITM. The AT&T TSD-3600 worked similarly.

This sort of protection is embedded in SSL, although no one uses it. As it is normally used, SSL provides an encrypted communications link to whoever is at the other end: bank and phishing site, alike. And the better phishing sites create valid SSL connections, so as to more effectively fool users. But if the user wanted to, he could manually check the SSL certificate to see if it was issued to "National Bank of Trustworthiness" or "Two Guys With a Computer in Nigeria."

No one does, though, because you both have to remember and be willing to do the work. (The browsers could make this easier if they wanted to, but they don’t seem to want to.) In the real world, you can easily tell a branch of your bank from a money changer on a streetcorner. But on the internet, a phishing site can be easily made to look like your bank's legitimate website. Any method of telling the two apart takes work. And that's the first step to fooling you with a MITM attack.

Man-in-the-middle isn't new, and it doesn't have to be technological. But the internet makes the attacks easier and more powerful, and that's not going to change anytime soon.

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Bruce Schneier is chief security technology officer of BT, and author of Beyond Fear: Thinking Sensibly About Security in an Uncertain World.