Bell Labs Researchers Spot Bluetooth Insecurities

Kyobu writes: "There's an article by John Markoff in [Saturday's] New York Times about insecurities in Bluetooth. The defects allow eavesdropping and caller identification." Markus Jacobson and Susanne Wetzel, both of Bell Laboratories, discovered weaknesses in the key exchange protocol currently implememented by Bluetooth. From the article: "The researchers are suggesting that the Bluetooth standard be altered so that the identity numbers are masked by a constantly changing pseudonym when transmitted." Considering the ubiquity many people expect Bluetooth devices to achieve, perhaps it's a good thing that this kind of attention starts early rather than late. (Complete with gratuitous Bruce Schneier quote.)

Comments

Bluetooth can o' worms

[zlite]

Actually, the whole concept of a peer-to-peer local area wireless network raises a host of issues. As I understand it, by default any Bluetooth device can "see" any other Bluetooth device in its vicinity. The point of this is that your cellphone/PDA can connect to everything from a wireless ISP server in your local Starbucks to the printer in your office, or simply trade info with another cellphone/PDA.

Obviously you will be able to set allowed access rules on the individual device, but can you hide the fact that you're carrying a Bluetooth device altogether?

To be useful for local-area communications (messaging across a classroom, for instance) the device would have to be as openly addressable as a telephone number. The difference being that, unlike a cellphone, the device itself automatically broadcasts that addressability (its phone number, as it were), which makes unwanted communications more of a risk. For instance: you're driving down the highway and some jerk cuts you off. You check your PDA and sure enough he's got a Bluetooth device in range. So you flame him! Far better than shaking your fist, huh?

Does anyone know what's being done to balance the privacy issue with the comminucations need for open accessibility?

Feelings about this Article

[hayfever]

I may be misreading this, so let me know if I'm wrong, but I believe it sounds like Bruce Schneier is against Bluetooth. I don't know the reasons behind it, or why he believes there are "too many things that can go wrong", but here are my feelings on the issue.

1) This is a protocol issue. It's basically saying that in the current form of the protocol, a machine's identity could be marked. Big deal. This is a completely new technology which is still being developed. When holes are discovered in technologies in wide use, there's a problem. When they are discovered in a yet-to-be released product, the problems can be fixed. Bruce is premature in his attack on Bluetooth.

2) Kudos to the Lucent team who discovered the problem. Not only did they search and find the problem, showing they are dedicated to this project and its security, but they told the world. It would have been all too easy to hide the problem and fix it, but they spread the word, even though the technology is not really in active use. This says to me again that they are dedicated to fixing the problems and keeping Bluetooth secure, which makes me more interested in using it. I'm not paranoid, nor do I feel like I'm a particular target for espionage, however, I enjoy my freedoms just as much as anyone else, including my right to privacy, and if Lucent and the rest of the developers are working to make sure I continue to enjoy that privacy, I'm just a little bit happier. Congratulations to the Lucent team and keep up the good work.

Re:It seems likely that

[quonsar]

Joe User cares when his identity is stolen and his bank account is wiped

yes, but he won't blame the technology. he'll know from the media that evil hax0r5 are to blame. and legislation to require licensing of all internet access tools and regulations to control internet content will have won a new lifelong supporter.

"I will gladly pay you today, sir, and eat up

Isn't security outside of it's domain?

[Nelson]

Isn't bluetooth the wireless equivelant of ethernet? Ehternet takes no security considerations in to mind, it is simply a transport layer and security is a higher level concern.

There are some subtle security issues since you can control the physical security of an ethernet lan and anyone can jack in to a bluetooth simply by walking in to range.

Schneier's Take on Bluetooth: Tempest, Closed Code

[mr. fabulous]

Actually, the whole concept of a peer-to-peer local area wireless network raises a host of issues.

Schneier's 8/15 Cryptogram newsletter touched on these issues weeks ago.

Namely, if capability like the US government's Tempest technology (reads electro magnetic pulses, CRT, keyboard radiation, etc. - spy craft stuff) is available, it's a matter of time before such tactics are _readily_ used on commonplace bluetooth devices doing private or delicate matters in public. After all, reading your OpenSSH-downloaded, and GnuPG encrypted email privately to yourself in the back booth might seem secure, but, what if a black hat type is capturing your radiating emissions quite easily? Illusory protection. Treat Bluetooth as a broadcast protocol, because that's what it is, says Schneier.

What amazes me is the dearth of information about the security of this protocol. I'm sure someone has thought about it, a team designed some security into Bluetooth, and that those designers believe it to be secure. But has anyone reputable examined the protocol? Is the implementation known to be correct? Are there any programming errors? If Bluetooth is secure, it will be the first time ever that a major protocol has been released without any security flaws. I'm not optimistic, continues Schneier.

Check out some of these articles on Bluetooth, and it's lack of discussion on it's possibly inherent security shortcomings.

Bluetooth

A list of Bluetooth articles, none of them about security

One mention of security

An essay about the Bluetooth hype

Recent article on TEMPEST

Me pican las bolas, man!
Thanks

Problems in protocols, analysis

[Submarine]

A little known fact in the general computing public is that problems in secure communications lie more often in the communication protocol than in the encryption primitives.

There are some classical attacks:

• Man-in-the-middle Idea: I can prove to both Karpov and Kasparov that I'm a great chess player. I challenge them both in a play through mail. I use the moves of each one against the other. Both think I play like a grandmaster.
• Use of old keys Idea: recover some secret data of a previous session (for instance from old temporary files on a common machine - after all, many operating systems do not really erase erased data). Use it in a current session.

It is possible to prevent those attacks by clever design of the protocol. For instance, the use of old keys can be prevented by some "nonce" numbers (generated once) or some clock data.

It is very difficult to analyse protocols and prove them correct.

First, a formal model of the protocol, its environment and what it means for it to be correct. This is nontrivial, since some models may just ignore some kinds of attacks.

Then the protocol must be proved correct with respect to the formal specification. Alas:

• manual theorem proving is error-prone
• formal theorem proving is tedious
• automatic analysis tools are not so powerful

I have made some research on these topics. For more information, see for instance Jon Millen's page.