Mythbusters and RFID

[error]

It will take one of those '3000' folks in the hacker audiance to take on RFID. 

RFID has been an ongoing issue for several people at Taproom Tuesday. We even did a bit of activism you might have heard of.

[John Edward Mercier]

Companies would need a reason to go to active tagging that can be made to go dormant, then re-awakened.

For the government to 'tag' you wouldn't require the cooperation of business. Most people will opt for cell phones, On-Star, Internet, or other such products/services that can handle the chore. Without any extra cost to business or direct government involvement.
But even for them, its a matter of noticing that your doing something they fear.

I've even seen this recently entering the biological field. People getting complete body MRIs to determine what shape they're circulatory system is in... or opting to get DNA testing. How many people have seen the option to get your children photographed and fingerprinted for security? Soon we'll see dentists and optometrist use digitized equipment and files.

[KBCraig]

Adam's a libertarian.

The whole show leans that way. I mean, c'mon, geeks with guns are almost automatically libertarian.

[Lloyd Danforth]

Adam may be a libertarian,but, I don't know about the other one. Every time a firearm comes into play he's all: "We gotta go get a cop to hold our hand!"

[AntonLee]

exactly, sometimes I used to wonder if it was something discovery made them say. . . but that guy sounds all too excited about the fact that some leo's need to be around to shoot a gun in a hard plastic case.   Scientifically, he might be a genius. . . but anatomically. . .he's got no nutsack.

[Josh]

Adam's a libertarian.

I kind of suspected that. He's too smart NOT to be

[Pat McCotter]

The first line of security is always obscurity... and no level of security is unbreachable.
You can't 'hack' what you don't know about... and anything can be 'hacked'.

Just one reason this is not true.
Why Being Open about Security Makes Us All Safer in the Long Run
By Bruce Schneier
The Guardian
August 7, 2008

London's Oyster card has been cracked, and the final details will become public in October. NXP Semiconductors, the Philips spin-off that makes the system, lost a court battle to prevent the researchers from publishing. People might be able to use this information to ride for free, but the sky won't be falling. And the publication of this serious vulnerability actually makes us all safer in the long run.

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, 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.

[John Edward Mercier]

Which part is not true?
Obviously they hacked the security... and if they did not know the security existed, would not have been able to hack it.

[Pat McCotter]

I think we may be miscommunicating here, John. You seem to be talking about a "security vulnerability" being secret as opposed to the "security system" being secret.

The Oyster card is a card that allows riding on subways. There must be readers for the cards at the subway entrance. This is the "security system." The card is secret but the card reader is public. The security system must be known to the card readers. If the readers must know the security system those who make the readers must know the security system. This is where the "security vulnerability" comes in.

If the security is weak and easily broken there will be more people able to use it - free rides on the subway. If the security is strong the value of what it protects must be higher for people to expend resources to break it - ePassport comes to mind here. Both systems use RFID chips so the security system is not unknown but security vulnerabilities may be - until an article like the one about Oyster cards comes out. That article was trying to show why keeping a vulnerability secret does not make a system secure.

This is not only a problem with computers. Key locks also have this security flaw. The key is secret but the lock is public. If the lock is protecting something of value there is more to be gained by trying to pick it. But picking of many locks on the market is not required. They can be opened with a "bump key." Watch this video to see a demo.

That Wikipedia article states that Medeco (amongst others) "are advertised to be bump proof." But this article shows that to be wrong - White House High-Security Locks Broken: Bumped and Picked at DefCon

Again, the security system can be public. If the system is strong it will require more resources to bypass it. Keeping vulnerabilities secret will make people feel secure but will not make them secure.

Having a secure system plays on some people's minds to try to gain access. That's what we humans are about. Game play is a way of looking for, and exploiting, vulnerabilities.

[John Edward Mercier]

Is the RFID the system? Or simply a component?
From what I'm reading the encoded 'lock and key' are the system.
So the fewer people (obscurity) that know about the 'lock and key' would be the first line of defense.

[dalebert]

I think it's likened to the argument against gun control. Those with ill intent have the greatest motivation to obtain guns for crime and so end up the only ones with guns. It's only an illusion of security. Look at all the open source software out there. It's much more secure because anyone can peruse it looking for flaws and make those flaws known so they can be quickly corrected.

[Pat McCotter]

RFID is different than the physical lock and key in that the lock (reader) queries the key (RFID chip) at a distance rather than coming into physical contact. RFID - chip and reader - is the security system. The chip is the key but it needs to let a reader know that it is there. Therefore those who want to get into whatever is under the lock many times just have to query the key and read the response. They then can clone the key.

If the key is encrypted then the hacker must know the encryption scheme used to decrypt the key to read it. In the case of the Oyster cards the encryption was "kindergarten cryptography." Supposedly the ePassport RFID is encrypted but ... how good is the encryption? Readers must still be able to read them, so the readers must have some sort of key to decrypt. How secure is that decryption key? This is where openness comes in - crypto experts should vet the system to see if it is actually secure.

Again, back to physical locks and keys there is a vulnerability with master-keyed locksets. It is possible to make a master key while having access to only one of the locks in the set. If a hacker has access to a passport reader can he get the "master" key?

[John Edward Mercier]

So the comparison is to reading the electric garage door opener's remote signal?
This is one of the things that they already knew about the RFIDs... that those with 'select' signals could be remotely read without the owner knowing and copied. Its why active tagging in most instances is crazy.

Open source code is a little different in that its public common property... so there is no secret to secure.

[dalebert]

Open source code is a little different in that its public common property... so there is no secret to secure.

But the point is that open source software can be implemented on a system to keep the system secure. So the software itself is not a secret, but it can keep secrets very well. The analogy would be that the information the RFID is supposed to protect can be secure while the method is very open so people can be confident that it's designed well. Lots of people know how Firefox works or Linux disk encryption, but good luck cracking it if the user has picked a complicated enough password!

[K. Darien Freeheart]

It's the difference between using rally good locks on your door or planting tall shrubs to conceal the doorless entry into your home.