### Commercial quantum cryptography system broken

http://www.technologyreview.com/blog/arxiv/25189/ Not at all to my surprise, they broke it by exploiting a difference between a theoretical system and a real-world implementation. --Steve Bellovin, http://www.cs.columbia.edu/~smb

### quantum cryptography broken?

http://www.kurzweilai.net/news/frame.html?main=/news/news_single.html?id%3D8471 Quantum cryptography broken KurzweilAI.net, April 20, 2008 Two Swedish scientsts, Jorgen Cederlof, now of Google, and Jan-Ake Larsson of Link In a paper published in IEEE Trans. Inf Theory, 54: 1735-1741 (2008

### Re: Quantum Cryptography

carry, ... and not vice versa. By that I mean: -- the integrity of DH depends fundamentally on the algorithm, so you should verify the algorithmic theory, and then verify that the box implements the algorithm correctly; while -- in the simple case, the integrity of quantum cryptography

### Re: Quantum Cryptography

At 5:11 PM -0400 7/2/07, John Denker wrote: By that I mean: -- the integrity of DH depends fundamentally on the algorithm, so you should verify the algorithmic theory, and then verify that the box implements the algorithm correctly; while -- in the simple case, the integrity of quantum

### Re: Quantum Cryptography

Alexander Klimov [EMAIL PROTECTED] writes: So what kind of threat models does it address, and what does that say about the kinds of customers who'd want it? One threat model (or at least failure mode) that's always concerned me deeply about QC is that you have absolutely no way of checking

### Re: Quantum Cryptography

At 08:51 AM 6/28/2007, Alexander Klimov wrote: I suspect there are two reasons for QKD to be still alive. First of all, the cost difference between quantum and normal approaches is so enormous that a lot of ignorant decision makers actually believe that they get something extra for this money.

### Re: Quantum Cryptography

a quantum key exchange and then falls back on classical primitives. It's at best confusing, fallacious and disingenuous to refer to such setups as quantum cryptography, though I understand classical encryption with quantum key exchange has less of a marketable ring to it. So, by all means

### Re: Quantum Cryptography

I'm unhappy with the tone of the discussion thus far. It's gone far beyond critiquing current products and is instead attacking the very concept. Today's cryptography is largely based on certain assumptions. You can't even call them axioms; they're far too weak. Let's consider RSA. We *know*

### Re: Quantum Cryptography

I suspect there are two reasons for QKD to be still alive. First of all, the cost difference between quantum and normal approaches is so enormous that a lot of ignorant decision makers actually believe that they get something extra for this money. If you tell a lie big enough and keep repeating

### Re: Quantum Cryptography

On Jun 26, 2007, at 10:10 AM, Nicolas Williams wrote: This too is a *fundamental* difference between QKD and classical cryptography. What does this classical word mean? Is it the Quantum way to say real? I know we're in violent agreement, but why are we letting them play language games?

### Re: Quantum Cryptography

On 6/25/07, Greg Troxel [EMAIL PROTECTED] wrote: 1) Do you believe the physics? (Most people who know physics seem to.) For those who would like to know a little more about the physics, see: http://www.icfo.es/images/publications/J05-055.pdf, Quantum Cloning, Valerio Scarani, Sofyan

### Re: Quantum Cryptography

On Tue, Jun 26, 2007 at 02:03:29PM -0700, Jon Callas wrote: On Jun 26, 2007, at 10:10 AM, Nicolas Williams wrote: This too is a *fundamental* difference between QKD and classical cryptography. What does this classical word mean? Is it the Quantum way to say real? I know we're in violent

### Re: Quantum Cryptography

Victor Duchovni [EMAIL PROTECTED] writes: Secure in what sense? Did I miss reading about the part of QKD that addresses MITM (just as plausible IMHO with fixed circuits as passive eavesdropping)? It would be good to read the QKD literature before claiming that QKD is always unauthenticated.

### Re: Quantum Cryptography

On Fri, Jun 22, 2007 at 08:21:25PM -0400, Leichter, Jerry wrote: BTW, on the quantum subway tokens business: In more modern terms, what this was providing was unlinkable, untraceable e-coins which could be spent exactly once, with *no* central database to check against and none of this well,

### Re: Quantum Cryptography

On Mon, Jun 25, 2007 at 08:23:14PM -0400, Greg Troxel wrote: 1) Do you believe the physics? (Most people who know physics seem to.) Yes. 2) Does the equipment in your lab correspond to the idealized models with which the proofs for (1) were done. (Not even close.) Does QKD address a

### Re: Quantum Cryptography

mechanism, and get PFS against an attacker who records all the traffic and breaks DH later. The end-to-end across middle boxes issue kills this argument about protection against speculative brokenness of public key cryptography. All but the smallest networks depend on middle boxes. Quantum

### Re: Quantum Cryptography

in what Dr. Duck says about physics? Usually not. == One commonly-made claim about quantum cryptography is that it can detect eavesdropping. I reckon that's narrowly true as stated. The problem is, I don't know why I should care. The history of cryptography for most

### Re: Quantum Cryptography

. It is only useful in key distribution. Let me create an aphorism to sum up what Paul, Perry, and others have said in detail before I address your comment: If Quantum Cryptography does what is claims, then it is strengthening the strongest link in the chain of security. Now to your

### Re: Quantum Cryptography

Victor Duchovni wrote: Quantum Cryptography or Quantum Computing (i.e. cryptanysis)? - Quantum Cryptography is fiction (strictly claims that it solves an applied problem are fiction, indisputably interesting Physics). I do not really agree on this statement. There are ongoing

### Re: Quantum Cryptography

- Quantum Cryptography is fiction (strictly claims that it solves an applied problem are fiction, indisputably interesting Physics). Well that is a broad (and maybe unfair) statement. Quantum Key Distribution (QKD) solves an applied problem of secure key distribution. It may

### Re: Quantum Cryptography

On Thu, Jun 21, 2007 at 01:20:35PM -0400, Victor Duchovni wrote: Quantum Cryptography or Quantum Computing (i.e. cryptanysis)? - Quantum Cryptography is fiction (strictly claims that it solves an applied problem are fiction, indisputably interesting Physics). - Quantum

### Re: Quantum Cryptography

On Thu, Jun 21, 2007 at 10:59:14AM -0700, Ali, Saqib wrote: - Quantum Cryptography is fiction (strictly claims that it solves an applied problem are fiction, indisputably interesting Physics). Well that is a broad (and maybe unfair) statement. Quantum Key Distribution (QKD

### Re: Quantum Cryptography

Massimiliano Pala [EMAIL PROTECTED] writes: Victor Duchovni wrote: Quantum Cryptography or Quantum Computing (i.e. cryptanysis)? - Quantum Cryptography is fiction (strictly claims that it solves an applied problem are fiction, indisputably interesting Physics). I do not really

### Re: Quantum Cryptography

| - Quantum Cryptography is fiction (strictly claims that it solves |an applied problem are fiction, indisputably interesting Physics). | | Well that is a broad (and maybe unfair) statement. | | Quantum Key Distribution (QKD) solves an applied problem of secure key

### Re: Quantum Cryptography

At 10:59 AM -0700 6/21/07, Ali, Saqib wrote: - Quantum Cryptography is fiction (strictly claims that it solves an applied problem are fiction, indisputably interesting Physics). Well that is a broad (and maybe unfair) statement. Quantum Key Distribution (QKD) solves an applied

### Re: Quantum Cryptography

On Fri, Jun 22, 2007 at 11:33:38AM -0400, Leichter, Jerry wrote: | Secure in what sense? Did I miss reading about the part of QKD that | addresses MITM (just as plausible IMHO with fixed circuits as passive | eavesdropping)? | | Once QKD is augmented with authentication to address MITM, the

### Re: Quantum Cryptography

Leichter, Jerry [EMAIL PROTECTED] writes: | - Quantum Cryptography is fiction (strictly claims that it solves |an applied problem are fiction, indisputably interesting Physics). | | Well that is a broad (and maybe unfair) statement. | | Quantum Key Distribution (QKD

### Re: Quantum Cryptography

...whereas the key distribution systems we have aren't affected by eavesdropping unless the attacker has the ability to perform 2^128 or more operations, which he doesn't. Paul: Here you are assuming that key exchange has already taken place. But key exchange is the toughest part. That is where

### Re: Quantum Cryptography

At 10:44 AM -0700 6/22/07, Ali, Saqib wrote: ...whereas the key distribution systems we have aren't affected by eavesdropping unless the attacker has the ability to perform 2^128 or more operations, which he doesn't. Paul: Here you are assuming that key exchange has already taken place. No,

### Re: Quantum Cryptography

On Fri, Jun 22, 2007 at 10:44:41AM -0700, Ali, Saqib wrote: Paul: Here you are assuming that key exchange has already taken place. But key exchange is the toughest part. That is where Quantum Key Distribution QKD comes in the picture. Once the keys are exchanged using QKD, you have to rely on

### Re: Quantum Cryptography

At 10:44 -0700 2007/06/22, Ali, Saqib wrote: ...whereas the key distribution systems we have aren't affected by eavesdropping unless the attacker has the ability to perform 2^128 or more operations, which he doesn't. Paul: Here you are assuming that key exchange has already taken place. But

### Re: Quantum Cryptography

Ali, Saqib [EMAIL PROTECTED] writes: ...whereas the key distribution systems we have aren't affected by eavesdropping unless the attacker has the ability to perform 2^128 or more operations, which he doesn't. Paul: Here you are assuming that key exchange has already taken place. But key

### Quantum Cryptography

Hi Folks, On a legal mailing list I'm on there is a bunch of emails on the perceived effects of quantum cryptography. Is there any authoritative literature/links that can help clear the confusion? Thanks in advance, Aram Perez

### Re: Quantum Cryptography

On Tue, Jun 19, 2007 at 09:10:12PM -0700, Aram Perez wrote: On a legal mailing list I'm on there is a bunch of emails on the perceived effects of quantum cryptography. Is there any authoritative literature/links that can help clear the confusion? Quantum Cryptography or Quantum Computing

### Toshiba shows practical quantum cryptography

http://www.zdnet.co.uk/print/?TYPE=storyAT=39181033-39020357t-1013c Toshiba shows practical quantum cryptography Rupert Goodwins ZDNet UK December 13, 2004, 18:15 GMT Toshiba Research Europe demonstrated last week what it claims is the world's first reliable automated quantum cryptography

### Re: Quantum cryptography gets practical

On Wed, 2004-10-06 at 06:27, Dave Howe wrote: I have yet to see an advantage to QKE that even mildly justifies the limitations and cost over anything more than a trivial link (two buildings within easy walking distance, sending high volumes of extremely sensitive material between them) But

### Re: Quantum cryptography gets practical

Dave Howe wrote: I think this is part of the purpose behind the following paper: http://eprint.iacr.org/2004/229.pdf which I am currently trying to understand and failing miserably at *sigh* Nope, finally strugged to the end to find a section pointing out that it does *not* prevent mitm attacks.

### QC Hype Watch: Quantum cryptography gets practical

http://www.computerworld.com/printthis/2004/0,4814,96111,00.html - Computerworld Quantum cryptography gets practical Opinion by Bob Gelfond, MagiQ Technologies Inc. SEPTEMBER 30, 2004 (COMPUTERWORLD) - In theory and in labs, quantum cryptography -- cryptography based

### U. of Tokyo, Fujitsu advance towards quantum cryptography

http://www.infoworld.com/article/04/07/23/HNquantumcrypto_1.html InfoWorld U. of Tokyo, Fujitsu advance towards quantum cryptography Project succeeds in generating single photo needed for securely sharing keys across telecom networks By Martyn Williams, IDG News Service July 23, 2004

### BBN Technologies Unveils World's First Quantum Cryptography Network

Technologies Unveils World's First Quantum Cryptography Network back Quantum Cryptography Breakthrough Delivers Absolute Security Based on Laws of Physics CAMBRIDGE, Mass., June 3 /PRNewswire/ -- BBN Technologies announced today that it has built

### EU seeks quantum cryptography response to Echelon

http://www.nwfusion.com/news/2004/0517euseeks.html Network World Fusion EU seeks quantum cryptography response to Echelon By Philip Willan IDG News Service, 05/17/04 The European Union is to invest ¤11 million ($13 million) over the next four years to develop a secure communication system

### RE: EU seeks quantum cryptography response to Echelon

Tom Shaddack wrote: On Tue, 18 May 2004, Tyler Durden wrote: Monyk believes there will be a global market of several million users once a workable solution has been developed. A political decision will have to be taken as to who those users will be in order to prevent terrorists

### RE: EU seeks quantum cryptography response to Echelon

advantage of the completely secure communication network, he said. Silliness itself, at this point. Practical quantum cryptography at this point is limited to transmission. The moment it goes O/E, it's as vulnerable as any other data. And terrorists aren't going to bother splicing fiber. Of course

### Bank Transfer via Quantum Cryptography Based on Entangled Photons

Sigh... The old hype-meter pegs so much the needle's bent... Cheers, RAH http://www.quantenkryptographie.at/rathaus_press.html Quantum Cryptography live World Premiere: Bank Transfer via Quantum Cryptography Based on Entangled Photons Press conference and demonstration of the ground

### Re: Quantum cryptography finally commercialized?

R. A. Hettinga wrote: http://www.net-security.org/news.php?id=3583 Quantum cryptography finally commercialized? Posted by Mirko Zorz - LogError Tuesday, 16 September 2003, 1:23 PM CET For the onlookers, this article is misinformed and should not be relied upon for evaluating quantum

### Quantum cryptography finally commercialized?

http://www.net-security.org/news.php?id=3583 Help Net Security - Quantum cryptography finally commercialized? Posted by Mirko Zorz - LogError Tuesday, 16 September 2003, 1:23 PM CET Start-up MagiQ Technologies, from Somerville, Massachusetts, has released the first commercial implementation