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.

This essay previously appeared on Wired.com.

EDITED TO ADD (8/26): Matt Blaze has a good essay on the topic.

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.

---

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.

Here's the story. Every Oyster card has a radio-frequency identification chip that communicates with readers mounted on the ticket barrier. That chip, the "Mifare Classic" chip, is used in hundreds of other transport systems as well — Boston, Los Angeles, Brisbane, Oslo, Amsterdam, Taipei, Shanghai, Rio de Janeiro — and as an access pass in thousands of companies, schools, hospitals, and government buildings around Britain and the rest of the world.

The security of Mifare Classic is terrible. This is not an exaggeration; it's kindergarten cryptography. Anyone with any security experience would be embarrassed to put his name to the design. NXP attempted to deal with this embarrassment by keeping the design secret.

The group that broke Mifare Classic is from Radboud University Nijmegen in the Netherlands. They demonstrated the attack by riding the Underground for free, and by breaking into a building. Their two papers (one is already online) will be published at two conferences this autumn.

The second paper is the one that NXP sued over. They called disclosure of the attack "irresponsible," warned that it will cause "immense damages," and claimed that it "will jeopardize the security of assets protected with systems incorporating the Mifare IC." The Dutch court would have none of it: "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."

Exactly right. More generally, the notion that secrecy supports security is inherently flawed. Whenever you see an organization claiming that design secrecy is necessary for security — in ID cards, in voting machines, in airport security — it invariably means that its security is lousy and it has no choice but to hide it. Any competent cryptographer would have designed Mifare's security with an open and public design.

Secrecy is fragile. Mifare's security was based on the belief that no one would discover how it worked; that's why NXP had to muzzle the Dutch researchers. But that's just wrong. Reverse-engineering isn't hard. Other researchers had already exposed Mifare's lousy security. A Chinese company even sells a compatible chip. Is there any doubt that the bad guys already know about this, or will soon enough?

Publication of this attack might be expensive for NXP and its customers, but it's good for security overall. Companies will only design security as good as their customers know to ask for. NXP's security was so bad because customers didn't know how to evaluate security: either they don't know what questions to ask, or didn't know enough to distrust the marketing answers they were given. This court ruling 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 unclear how this break will affect Transport for London. Cloning takes only a few seconds, and the thief only has to brush up against someone carrying a legitimate Oyster card. But it requires an RFID reader and a small piece of software which, while feasible for a techie, are too complicated for the average fare dodger. The police are likely to quickly arrest anyone who tries to sell cloned cards on any scale. TfL promises to turn off any cloned cards within 24 hours, but that will hurt the innocent victim who had his card cloned more than the thief.

The vulnerability is far more serious to the companies that use Mifare Classic as an access pass. It would be very interesting to know how NXP presented the system's security to them.

And while these attacks only pertain to the Mifare Classic chip, it makes me suspicious of the entire product line. NXP sells a more secure chip and has another on the way, but given the number of basic cryptography mistakes NXP made with Mifare Classic, one has to wonder whether the "more secure" versions will be sufficiently so.

This essay originally appeared in the Guardian.

When we boarded a little later, I asked for the ninny's name. He refused and hissed, "If you make a scene, I'll call the pilot and you won't be flying tonight."

The credit controller, from Gloucester, says he now suffers "appalling" abuse from the authorities and public who doubt his motives. The bus-spotter, officially known as an omnibologist, said: "Since the 9/11 attacks there has been a crackdown. "The past two years have absolutely been the worst. I have had the most appalling abuse from the public, drivers and police over-exercising their authority. Mr McCaffery, who is married, added: "We just want to enjoy our hobby without harassment. "I can deal with the fact someone might think I'm a terrorist, but when they start saying you're a paedophile it really hurts."

Israeli authorities are investigating why a Palestinian resident of Jerusalem rammed his bulldozer into several cars and buses Wednesday, killing three people before Israeli police shot him dead. Israeli authorities are labeling it a terrorist attack, although they say there is no clear motive and the man -- a construction worker -- acted alone. It is not known if he had links to any terrorist organization.

Turns out the ninja was actually a camp counselor dressed in black karate garb and carrying a plastic sword. Police tell the Asbury Park Press the man was late to a costume-themed day at a nearby middle school.

Amsterdam police say 15 camels, two zebras and an undetermined number of llamas and potbellied swine briefly escaped from a traveling Dutch circus after a giraffe kicked a hole in their cage.

Those so-called Afghan National Auxiliary Police (ANAP), all formerly in the service of local warlords, had received two months of training by Dutch and American soldiers and were now the first line of defense against the Taliban.

Arming tribesmen was a risky idea. True, this sort of tribal initiative had been effective in Iraq. But NATO commanders feared that Afghan loyalties to their warlords ran too deep. NATO was “arming people who were not necessarily in line with the [Afghan] government,” U.S. Brig. Gen. Robert Cone told Wired.com.

So, last month, NATO fired the auxiliary cops and scrapped the tribal strategy, leaving gaping holes in Afghanistan's defenses. The fix? Marines, of course, armed with fingerprint pads, iris scanners and electronic databases.

With these biometric tools, the Marines are planning to recruit new cops who have no ties to tribal warlords. “We know there are some shadow police and some militia-type police,” Lt. Col. Ray Hall, the Marine commander, said. “Once we go through the vetting process, we'll have everybody screened … so that problem should go away.”

That means scanning every new recruit's unique iris “eye prints,” logging their thumb prints and feeding it all into a growing, but still very spotty, national database linked to criminal and intelligence records. If a cop has any known warlord ties, he's disqualified from serving.

CIA teams used FBI biometrics while hunting for known Al Qaeda operatives in Afghanistan in 2001, and since then, the military has gathered data on almost every Afghan it comes in regular contact with.

There's one more problem. Not all the military databases can talk to one another. “We haven't standardized,” said Larry Schneider, a Northrop Grumman VP who last year was working on collapsing many biometrics systems into just one.

Until everyone is looking at the same data, seditious Afghan cops will probably keep falling through the cracks.