Slashdot Mirror
Cracking GSM
RobertM writes "Professor Eli Biham, one of the worlds most famous crypto analysts, together with two of his students presented an interesting paper on flaws in GSM at the IACR Crypto conference. The GSM association is not happy. Read more on theReg." There's also a Reuters article about the situation.
I wonder how long it will be till they attempt to use the DMCA to silence him - this is after all a typical scenario for the DMCA to be exploited in order to gag scientists and cryptology experts.
Sadly, I wouldn't at all be surprised to see this end up on chillingeffects in the near future.
The US CIA, UK M5 and Israel Mossad are now hiring people with experience with GSM and crypto experience.
I always thought a funny and interesting practical application of cracking GSM, or pretending to be a mobile phone mast through other means would be to ring everyone's mobile up in the area at the same time and have them all talk to each other. That would be excellent!
I don't see how this is news, I've known about this for months, I heard them talking about it on their GSM pho- uh, nevermind.
The International Journal of Digital Evidencehas a current article about GSM forensics.
"The paper was presented at last month's Crypto Conference in Santa Barbara, California but news of this alarming discovery only broke yesterday."
Because most of the attendees were sleeping after a heavy lunch and martinis.
1. Does DCMA and its cousins allow such methods to be patented?
2. Will the phreakers care about patents?
nothing!
but if the scientists came from an Arab country, they would have been nuked for that...
the UK M5 is a road. perhaps you mean MI5?
that just as the mobile phone companies are desperate to move people on to the next generation of mobile technology, it is revealed that an older technology is flawed.
Amazing.
Don
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Eatthepuddingeatthepuddingeatthepudding
Slashdot - The Home of the Tortured Analogy
Illegal interception of calls will be prevented by patenting the technology?
I'm sure that a criminal really cares about patent infringements.
Laws should not be used to shore up broken technology. This only impedes law abiding citizens, and does nothing to improve the protection against crime.
This one arguement against gun control, make them illegal and only criminals will have guns.
Make this illegal and only criminals will listen to your phone call.
Elad, Nathan, Eli Biham and Orr Dunkelman (which was not listed for some reason) are friends of mine at the Technion Israeli Institute of Technology. Their previous attack on A5/1 required a few hundred GB of HD space and dedicated telephony equipment to pull. A5/2 is a peace of cake in comparison. This new attack makes it ciphertext only. That means that you don't have to initiate a short call (for example) to the evesdropee or knowing some part of the call (like with voicemail) before breaking the encryption. It uses the signal correction mechanism to initialize itself.
In general, this is no big news, because this equipment is hard to aquire and the benefits are not that great. In comparison, CDMA and TDMA don't (effectively) encrypt calls at all.
Make even shorter URLs - 8LN.org
Last time I told a software manufacturer about security flaws they were like, oh we don't care - our users are too dumb to work it out. Uh huh, but what about the competition? I'm sure their opinion would change had I released an exploit for it.
Similarly, the GSM Association probably knew about it, it's probably a designed-in backdoor to allow governmental evesdropping, but now it's public knowledge they're unhappy. Notice they say "very difficult" to exploit - not impossible. They know what's up, and they should've done better.
Well boo hoo GSM. If you've got flaws, fix them - don't go whining when someone finds you out and talks about it. No software is perfect, and trying to pretend otherwise (incl. with DMCA court action) is just a revised addition of The Emporers Clothes.
Forget thrust, drag, lift and weight. Airplanes fly because of money.
According to Reuters, the Association claims an attacker would have to "transmit distinctive data over the air to masquerade as a GSM base station". An attacker would also have to be placed between a caller and a base station to intercept a call, it adds.
So, it's possible to intercept calls by mimicing a base station by placing yourself where a base station could be? Sounds awfully like a game of monkey-in-the-middle to me.
My generalization probably makes this seem more "duh, obvious" than it likely is.
I have been looking for a good source on the security of CDMA (2000 - 1X, but also CDMA). I have found the basic stuff using google, but is difficult to find real info given that almost all the google results are for press releases or biz-talk from the technology providers (qualcomm, ericsson, motorola, etc) and all of them state "great security".
The question is can somebody deploy a off-the-shelf (or homebuilt) scanner and grab the conversations on-the-air? I know that a PR (pseudo random) number is used with the ESN and A-key to generate some keys for encrypting some of the communications, and that the voice channel is "scrambled", but is there a source where the security implications of this is discussed?
Also interesting is that this article appeared (or was going to) on yesterday's slashdot edition but after being available for subscribers for a while it dissapeared.
Life isn't like a box of chocolates. It's more like a jar of jalapenos. What you do today, might burn your ass tomorrow.
Countries cannot prevent this type of research, they can only censor it after the fact. I find it hard to believe that the Israeli government was monitoring all university programs of study to prevent violations of a law a dozen timezones away just so that their buddy-buddy (read: lapdog) doesn't get all upset.
And if they are, that's no democracy.
The encryption is only between the handset and the base station. The goverment can easily evesdrop at the cellular provider (after issuing a warrant).
Make even shorter URLs - 8LN.org
"they can hear you now."
"they can hear you now."
From theReg...
Both parties agree that the issue does not affect 3G phones, which use different protocols and security mechanisms than legacy GSM handsets.
Hmmm. If I remember well, other Israeli crypto researchers, including Pr Shamir (of RSA fame, Rivest - Shamir - Adelman) mentioned a couple of years ago that GSM crypto could, theoretically, be cracked almost in real time by a (relatively) low-powered machine.
GSM specialists have known for a number of years now that GSM crypto was not that good. Interestingly enough, GSM crypto was designed by French 'military specialists', which has raised the usual (probably justified) suspicions of backdoors.
Sorry for not being able to produce more info, but I am sure other Slashdotters will have interesting links to supply...
The right to offend is far more important than the right not to be offended. (Rowan Atkinson)
The novelety of this attack is that it is instantanous. The cryptanalysis is done one when the call is being established (when the phone just rings) even before any any real conversation is being done.
The exact details are still secret but the attack exploits a misuse of Error Correcting Codes (ECC - are used in communication protocols to correct random noise errors).
It seems that instead of encrypting the conversation and then employing ECC, the GSM does it the other way thus leaking enough data for the cryptanalysis to be performed
Not only does the US fund the weaponry that allows the illegal incursions into Palestinean soveriegn terrority (in the name of "the war against terrorism"), it allows the Israeli people to have one of the highest standards of living in the Middle East while families in Palestine starve and worry about food, clean water and medical care.
.
And Americans cry and wail and wonder why (and I actually heard this coming from some Midwestern mother of three after some recent attacks in the Middle East) why do they hate us so much? They must hate our freedoms
Yeah, that's it. They hate our freedom. Look how we continue to support a regime that enslaves and subjugates the Arab people of the MIddle East for the US's own oil thirst. No wonder this is the stupidest country on the planet.
Karma: Excellent Birds (mostly as a result of listening to Laurie Anderson)
DMCA stands for Digital Milennium Copyright Act, and prevents the circumvention or cracking of copyright prevention, not of just any form of encryption.
Sure, some lawyer will be able to construct a lawsuit out of this using the DMCA as a leverage, especially since this news will allow people to spread massive amounts of FUD in order to make a quick buck from the techno-illiterate masses, but I don't think the DMCA is violated here.
I don't think it will affect US/Israel relations. The relation the US has with Israel is mostly born out of the massive jewish lobby in the US, who indirectly determine the course of the nation, just like for instance the NRA or the entertainment industry is doing. In order to alter the relation between the US and Israel, you must alter the realtion between the jewish lobby in the US and Israel, and I don't think that's something we'll see soon...
Stupid job ads, weird spam, occasional insight at
It has long been suspected that GSM encryption was specificaly designed with some 'weak spot' to allow law-enforcemant monitoring.
Does anyone know if the article is available online?
I'd like to know if this flaw looks more like a mistake or somthing more intentional.
None of the meadia people who spoke about it seem to understand that "Instant Ciphertext-Only Cryptanalysis" means you are effectivly not protected at all.
As of Postgres v6.2, time travel is no longer supported.
At least they point out that the equipment required costs about $250k.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
Finally one reason for people to upgrade to 3G.
Just saying it like it are.
Prof. Eli Biham and Elad Barkan. Both good friends of mine.
Make even shorter URLs - 8LN.org
From http://israelemb.org/sanfran/News&Media/full/03/se p/02#c
"Elad found that the GSM network does not work in proper order: First, it inflates the information passing through it in order to correct for interference and noise and only then encrypts it," Biham told The Jerusalem Post. "At first, I didn't believe it. We checked it, and it was true."
That probably means higher predictability for the encrypted data.
my other sig is a 500 page novel
REMOB anyone?
...."
REMOB (Remote observation mode) is a TSPS console feature of the american telephone system to allow inward ops to monitor a suspected phone that might be "off the hook" prior to interrupting the line for "life or dire emergency" with the 500Hz tone and issuance of the frequently heard phrase "This is the att operator do you wish to disconnect this call you have an emergecy phone call from
but PRIOR to that for 30 second maximum bursts you get to hear an inverterted sound wave... which you can record.
better... the fbi has is setup to cascade overlapping series of REMOB snippets so when one ends (on any CLASS capable ESS r5) another takes over.
This way no interrupt chirp is heard by the victims, and lots of trivially "scrambled' speech can be secretly recorded.
i have never ever ever seen this in print or any edoc in history of phreaking.
I have seen telephon reps state to congree that REMOB did not exist.
it exists.
it does not take outside intercepts (ECHELON) as reported on 60 Minutes, or any NRO or NSA budgets,
it only takes a 6 digit code and the correct connections to do REMOB.
REMOB makes intercepting cell phones laughable in comparison.
besides... the German Gov records ALL cell phones under that alleged statement that in theory it COULD intercept the airwaves anyways if they tried. Remeber the slashdot article?
also the us gov allows no-warrant affixing of GPS locater emmitter bugs under your car frame under the assumption that it could visually track you from their air if they had the money anyways. Remember the Scott peterson case this summer? No initial warrant to put the gps bug on his car.
recording and intercepting ALL cell phone traffic at the point of origin on the LAND LINES is what the fed gov assumes is their right!
no need to mess with intercepts.
July 1983 the us supreme court ruled the public had a right to intercept and use all radio trasmissions INCLUDING call phones. Then they pverturned it partly years later.
today it is LEGAL for the cops to buy and sell equipment to record cell phones, but not the public across state borders. you have to build it from scratch yourself for your own hobbyist needs... and then its legal to use.
but REMOB is far far more humorous.
I know it exists.... first hand
From the Reg article:
I don't have the sales figures to hand, but I don't think GSM can really be called a "legacy" technology yet. IIRC Britain only has one provider 3G service provider, which has had a fraction of the expected number of subscribers.
"The Milliard Gargantubrain? A mere abacus - mention it not."
In the bad old days of analog mobile phones, there wasn't even encryption on the signal. You could literally walk into Radio Shack and walk out carrying a scanner capable of receiving mobile phone frequencies. (They eventually banned the sale of scanners capable of receiving those frequencies.) Later, TDMA and CDMA technologies made it more difficult to intercept signals, but all that's required is the right decoder.
Encryption of the call is a fairly recent trend and I think it's a terrific idea, but any encryption can be broken in time. While the odds are low that someone may be listing in, guaranteed privacy is impossible.
I think as a whole, we tend to trust in technology without really understanding it. I'm reminded of two engineering students who were visiting my apartment in college, and showing off their new cell phones by one calling the other. They were quite surprised when I was able to intercept their call with a cheap radio scanner. They had no idea their call was not private, simply assuming that the technology was secure. It wasn't.
He also spelled "seam" or seem wrong
But his ideas are right. And Israel has been retaliated by all of its neighbors.
When you oppress people for so long, they will retaliate the only way they can, through suicide bombing and other means.
[I can picture a world without war, without hate. I can picture us attacking that world, because they'd never expect it]
18:00-20:30
Beach Barbecue
Bar 18:00-20:30
Buffet 18:15-20:30
Dessert/Coffee 19:00-20:30
I wasn't there but I just know that everyone showed for the beach barbecue with the open bar and grub all night long.
From excellent karma to terible karma with a single +5 funny post...
So you argue that we should not have retaliated
the nazist? And that the US should continue to arm
Nazist when slaughtering Judes, Homosexuals and
other disturbing ellements? I, for myself, think
that if *any* country, Israel should know better.
Or maby you call the resistance (judish and other)
in europe just terrorist that did not like the
freedom offered by the nazis???
I can not spell good because I am not that great
at speaking or writing english.
So if professor publishes this, its all fine and dandy, but when a citizen publishes an eBook hack he's arrested? What gives?
This is a test. This is a test of the emergency sig system. This has been only a test.
I thought that you were a history buff.
Genocide is what you want? They are in an open state of war that is stagnating because doves won't allow Israel to simply push all the Palestinians into the sea - as they should have done long ago.
I thought after rarely escaping that, the Jewish people would not want to ever do that to anyone.
Discrimination is clouding your judgement
[I can picture a world without war, without hate. I can picture us attacking that world, because they'd never expect it]
Now all psychos will have to pay me in order to perform their activities.
DVD Ripping, Divx, VCD, SVCD under Linux
Why should all of these law enforcement agencies go through all these troubles? Why not just go to the telco and ask them nicely, I know that some countries (The Netherlands for instance) only give out GSM licenses to telco's who are willing to record all of the conversations done on their network. Law enforcement agencies must have Access to this database. I'm sure The Netherlands isn't the only country with this kind of "license restriction". The stuff needed for this type of eavesdropping is expensive and I think in most countries irrelevant.
Criticism, however, allowed him to improve himself.
They say the first thing to go is your penis. Well, it's either that or your brain. I forget which...
If this cracking method is indeed patented then it must be publicly released for anyone to read and understand. But public release would seem to violate DCMA and stifling the publication would seem to violate the constitutional underpinnings of the patent system (to encourage innovation by both granting monopolies and making inventions publicly accessible for further innovation). Does this make DCMA unconstitutional???
Two wrongs don't make a right, but three lefts do.
Well, since the religion card has been played...
"I thought after rarely escaping that, the Jewish people would not want to ever do that to anyone."
Maybe it's the Christians in conspiracy, using the Jewish Israelis without their realization, to get back at the arab world for forcing the Christians into the sea at the end of the Crusades...
Rome has been awfully quiet about the whole affair, after all...
The preceding post is categorized as sarcasm, for the humour impaired
Do not look into laser with remaining eye.
The Israelis have done nothing to show they want peace.
And as for your "Palestinians arent a race" arguement so you can kill them all and its not genocide...that is outrageous. So you can kill all the Jewish people in North America because well, hey! theres more in the world!
That is idiotic.
[I can picture a world without war, without hate. I can picture us attacking that world, because they'd never expect it]
The article states... The GSM Association admits the Israeli researchers are onto something but say the attack requires the use of complex technology, which few phone phreakers have access to, and would need to be targeted at a specific caller.
I see ... in other words. They only people you have to fear is your government and large companies.
Is anyone else bothered by the fact that governments all across this planet of ours seem to think that the only kind of secrecy that is a good thing is goverment secrecy?
This is an ex-parrot!
- The GSM association is not happy.
They should be happy. It's an opportunity to them to refine their techniques and improve users protection.IMO people should understand that errors found are opportunities to improve quality. Not a way to point incapacity.
-=-=-=-=
I know life isn't fair, but why can't it ever be un-fair in MY favor!?
The problem is that it's a terrible situation for everyone over there. Surely everyone has a right to live in peace, and surely that's what most people, Palestinian and Israeli, really want. However, the problems there have become a proxy for everyone else in the world to line up against each other. Arab leaders use it to strengthen their position by distracting their people from their own problems. It has become a platform for conservatives and liberals in this country to each claim the moral high ground on, and to demonize each other.
Somehow, the world gets much more out of the conflict than it gets out of a peaceful resolution. If everyone thinks one side is truly evil, than only that side's elimination or expulsion is satisfactory. So how can peace be satisfactory to the world? Does the Arab world really have an interest in ending the conflict? Do people in the U.S. using it to demonize their political enemies on both sides have an interest in it ending?
I would like to go back there some day with my family and visit all the holy sites, wherever they may be, without fear of being wounded or killed. That is part of my stake. What is the rest of the world's stake?
It's not wasting time, I'm educating myself.
The encryption is in the phone, so the phone needs to be upgraded.
From the article on the Register:
"Both parties agree that the issue does not affect 3G phones, which use different protocols and security mechanisms than legacy GSM handsets."
You DO have one of the new phones, right? I mean, you ARE reading Slashdot.
I think this is what's going to keep it from being a problem legally - nobody's introducing phones to which this attack is vulnerable.
Dare to Hope. Prepare to be Disappointed.
If you look at the United State's military budget, you would see that it is larger than most(if not all) of the world's military budget combined.
Do you think that Russia, any European country (and I will be nice and not pick on France), China or India could possibly deploy the same volume of troops and equipment in the same time span as the US?
If you are a student of Network Centric Warfare, then you would know that only the US of A has the current capability to land a certain number troops in any spot in the world in under 96 hours.
Should I even mention what country has developed the most advanced weapondry the world has ever seen? Russia may have some great engineers but they lack the capability to actually produce working and reliable weapondry. They have great ideas, but their implementation sucks. The Chinese and Indian's just copy whatever we develop.
Do you really think that Europe would throw in with the Chinese, Russians, and Indian's if Great Britain stayed out of it or even threw in with the US?
I think not!
Not to mention that the Russians and Chinese hate each other completely and the chinese and indian's aren't on the most friendly of terms either!
So... yes, I do believe that in a non-nuclear fight, we would beat Europe, China, Russia, and India.
ControlBooth.com
Technical Theater Made Easy!
A: No.
The hash function (A3/A8) used in the default implementation of the GSM protocol for the challenge-response authentication had a vulnerability of a type known about in the cryptographic community for years.
This wasn't a deliberate weakening, because this flaw had no real impact on the ability of law enforcement to intercept, and allowed cloning of GSM handsets: something that was definitely not supposed to be possible.
They've learnt from their mistakes though: the 3G protocol has undergone extensive public review , as has the ciphers they chose.
Hey, believe it or not, the US doesn't have legal jurisdiction in other countries.
That's right, I can drive on the left side of the road - AND NOT BE ARRESTED FOR BREAKING US TRAFFIC LAWS!
--
This sig is inoffensive.
The only other reason I can see for him not being arrested is the fact that GSM is not a US owned technology. That and the fact that operators couldn't care less, it is not like they hold copyright over your conversations...
in many countries, GSM operators are required to turn encryption off.
"...instead of encrypting the conversation and then employing ECC, the GSM does it the other way...."
Well, that answers my question about whether the standard writers had their design reviewed by someone who understands cryptography. *sigh*
Kindly don't feed this troll anymore. It's obvious he doens't know what he's talking about - he's made false claims that Arafat and the Palestinian Authority is a terrorist/supports terrorism (which is untrue, probably got that from US/Israel propaganda without researching first), claims that the Palestinians don't exist (unfortunately there are a few million of them now, so they exist whether the Israelis and this jerk likes it or not), and notice the double standard when he claims that the Palestinians should have been annhilated/pushed into the sea etc., yet condemning the (foolish) attempt by a bunch of (foolish) arab leaders when they tried to do just the same to Israel in the late 1960's!
Unfortunately, this is a view held my many ignorant Westerners who know nothing of the situation, and blindly believe all the propaganda from the governments and the media, and flatly refuse to believe that Israel is one half of the problem!
Good to know that pretty much the whole world now seems to be on 3G, why else would the article speak of "legacy GSM handsets"?
I hear them referred to as Brittish foreign intelligence all the time.
Well you see, its one higher.
You are in a maze of twisted little posts, all alike.
I don't know, but I'm feeling that this is somewhat not true... If a cell phone processor can decrypt the code (not crack it!) so quick, how come a 2Ghz processor can't crack it? Advice for those of you who already area midway through the solution to this problem: Try locating the university's servers... []'s magu
I'm leaving! And I took the kids! You can keep the dog. Signed, Your Sig
America is invincible. Other countries will never advance any farther than America wishes them to advance.
Carthage was invicible until Rome turned up.
Rome was invincible until the 'barbarians' turned up.
The Inca were invincible until the Spanish turned up.
There is a proverb from Belarus - Keep one eye on the past and you are half blind. Forget the past altogether and you are totally blind.
--
This sig is inoffensive.
However, I am interested in what facts you have to back up your statement:
"Still, your post is misinformed nonsense, but you can't help believing what your press says."
I also will carry the burden of proof if you should decide to challenge me on any of my facts.
Sincerely,
David
P.S. -It only took me about 2 minutes to type that last post, I am a fast typist.
ControlBooth.com
Technical Theater Made Easy!
For USians, the roles equate as follows:
MI5 = FBI
MI6 = CIA
GCHQ = NSA
JIC = Senate Oversight Committee (*very* roughly)
UNIX? They're not even circumcised! Savages!
BTW, if you haven't already read this book & are even slightly interested in security, I can strongly recommend it. It covers everything from smart cards, nuclear command & control, radio monitoring, GSM, ATM & credit cards, biometrics, through to the standard encryption protocols & e-commerce.
here is your cookie...
Oh, and 3G calls to GSM mobiles are presumably still open...
GSM is a published algorithm, is it not? As such, he wouldn't have to reverse-engineer anything. I don't believe the DMCA covers criticizing something that has an open spec. It's not his fault he's the only one who had the insight.
-Looking for a job as a materials chemist or multivariat
True, hopefully they'll act legally when dealing with domestic carriers, but internationally, it's a totally different story. No Chinese carrier is going to allow the US government to tap in. Heck, even British Telecom probably wouldn't let them... and even if they did, the US government would want to absolutely minimize the chance that the victim could find out about the tap -- and a good step towards that is keeping all information within their own organization (and not in the hands of a private or foreign-governement-owned phone carrier)
HIV Crosses Species Barrier... into Muppets
CDMA is indeed tougher to demodulate than GSM, the reason being that each GSM signal uses the same carrier (basically it encodes bits by modulating phase; the technical term is Gaussian Minimum Shift Keying, or GMSK). CDMA, on the other hand, has each user use a different "spreading code" in an attempt to make signals from different users orthogonal. The purpose of the spreading code is to take your nice orderly stream of bits, and turn it into a random-looking sequence. At the other end, the receiver knows what sequence you're using, and it can undo this transformation. As a side effect, your code is chosen to try to be orthogonal to other people's codes, so that at the same time demodulating your signal nulls out other people's signals, so your interference is reduced.
The reason there's some security in this process is that if a 3rd party doesn't know your spreading code, they won't be able to demodulate your signal -- you're going to sound like so much noise to their receiver, even if they have the proper CDMA decoding hardware. Having said that, this "encryption" supposedly isn't difficult to crack; Phil Karn from Qualcomm posted a discussion on CDMA security to a crypto list about this a while back. Here's a snippet:
I remember hearing a lecture on CDMA where the professor described a favorite tactic of hackers being to hang out with scanners over bridges, where people's connections would cut out, and grab their codes when the phones tried to resync with the base stations as cars exited the tunnel.
The bold print giveth, and the fine print taketh away
Fun with Anagarams! LADS HOST, SHALT DOS. HAS DOLTS. AD SLOTHS, HATS SOLD. ASS HO, LTD.
I don't even have a cell phone, let alone a 3G model :)
...you insensitive clod!
The report says you need to play man in the middle, the paper title claims cyper text only. Does anyone with the relevent background know which it is?
_O_
.|< The named which can be named is not the true named
Does anyone know if its possible to make a device that exploits such a vulnerability?
I don't buy into the very difficult to exploit crap. As far as I can tell from this information (but IANAHE - im not a hardware engineer) it would be possible to design hardware that can systematically exploit this vulnerability and it would be a godsent for governments of countries with less than adequate constitutions and really handy to have for large companies who would like to hear what their competition has to say. It would be an extremely valuable device. Very difficult to exploit in practise, maybe, worth it to some? totally..
Of those to whom much is given, much is required.
"There are already a million monkeys on a million typewriters, and Usenet is NOTHING like Shakespeare." - Blair Houghton
The GSM says the attack is difficult and expensive
to implement, I am not so sure.
I havn't read the papers my self but I do
discuss cryptology with Elad on a regular basis,
It is my understanig that besides the weakness
Elad found, they plan on using some time/memory/data
tradeoff to actually preform the attack.
The error correction code fiasco just elimenates
the need for some known plaintext(as was needed in
previos attack by Dunkekman(Who, epsalon you might
know had littleto do with this new attack).
If I understand things correctly, you need
significant computer power to get going, but
after your done preprocessing, also a very weak
cmputer with a cell-phone attached to it,
will be able to listen in on any call, easily.
I don't have numbers as to how easy is this
exactly.
I would recommend reading up, the following
article showen in crypto right after:
Making a faster time/memory tradeoff.
and another paper on
stream ciphers with low sampling rates.
This is what Elad has been reading up on,
probably has a lot to do with this attack.
seems to me the GSM are not being accurate.
But you can't.
The error correction is there to cope with the multipath fading environment that distorts the radio channel. Without the error correction the encrypted data you decrypt would be garbage and would not decrypt to what it was originally.
-- BtB
Troll? Nope, just replying to the OP's myopic view of American 'invicibility.'
--
This sig is inoffensive.
It's "an anonymous tip"...
Why is this flamebait? Each side thinks the other is a terrorist. Has Slashdot picked an official side, rendering any who have differing opinions as trolls?
The initial work didn't totally blow the system open and make on-the-air cracks easy, but it showed that the system was incompetently designed as well as deliberately weakened further, and was yet another reminder that Closed System Design is even worse in cryptography than in software. Subsequent work by people like Biham and Wagner keeps making it worse, and of course computer equipment keeps getting cheaper and larger, which means that attacks that need "hundreds of GB of disk" cost you $200 at Fry's rather than $200000 at the NSA Spook Equipment Shoppe.
In the US, GSM is still a security improvement, weak as it is, because the government bullied the digital cell phone system developers into using even weaker and more broken algorithms (back when they could pretend they were worried about Commie Spies rather than trying to facilitate illegal wiretapping.) (And of course analog cell phones didn't have crypto at all.) But even then, many of the cell phone companies don't bother turning on the crypto - Nokia phones give you a nice friendly indication that they tried to use it and got rejected.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
At great risk of sounding like the Voice of Reason (and God knows how Slashdotters hate that!), could you please present some evidence to back up your assertion that the United States and United Kingdom are colluding to break the laws of both nations?
Look up the Federal laws: if it is illegal for a Federal agency to do $foo, then it is also illegal for a Federal agency to have a third party do $foo on their behalf.
If I break into a home and see a kilo of cocaine lying around, I can then go to the DEA and tell them. They can use my testimony to get a warrant to search the home and impound the drugs. Why? Because I didn't commit the crime on their behalf; I came in entirely of my own accord; there was no understanding between the DEA and myself that "if I see any drugs, I'm going to bring them to your attention".
But if the DEA asks me to break into a home, they'd better damn well have a warrant, otherwise they're breaking all manner of Federal laws.
So what you're positing is there is a tacit understanding between the US and UK that each will spy on the other's citizens and share with each other the fruits of those actions. Hmm. This sounds mind-bogglingly stupid.
Why?
Free hint: this is a Federal crime.
Free hint number two: the FBI and NSA do not get along.
Free hint number three: the FBI is the one with the charter to spy on American citizens--not the NSA.
Free hint number four: the FBI protects its jurisdictional turf very zealously.
Free hint number five: the FBI is one of the nation's intelligence agencies, co-equal with the CIA and NSA. The FBI has no charter to collect intelligence from foreign sources; the CIA and NSA have no charter to collect intelligence from domestic sources.
Free hint number six: if the NSA were to really be involved in this, the FBI would be doing a full-court-press investigation into the matter. (a), because it's a clear and massive violation of Federal law, and more importantly, (b) THE FBI DOES NOT SHARE ITS JURISDICTIONAL TURF.
Period.
So if you have any hard facts proving this tacit agreement, I'd love to hear it. If you have hard facts about it, then I'll talk to my FBI friends tomorrow and tell them about it.
I guarantee you they'll be pissed off.
Stole your lawyers cell phone, hacked it in your "cell" and passed the codes on to your wife during a visit eh?
And you have the BALLS to beg to be set free after all this??!!
BAH! I think not!
-1, Tinfoil Hat Conspiracy.
!#@%*)anks for hanging up the phone, dear.
Does anyone have more information on this? Typically if you decrypt something which has errors, those errors become greatly magnified, and error correcting codes would have a very hard time fixing those errors. I'm wondering if the attack is exploiting something about the equalization training sequence and not so much error correcting codes.
If they are using a LFSR (linear feedback shift register), a popular circuit for generating pseudo-random bit sequences, it isn't secure. Simple LFSRs are trivial to crack.
Mea navis aericumbens anguillis abundat
From what I remember, the design of the GSM A5 cipher was always suspected to be weak. From Applied Cryptography:
Bruce Schneier then goes on to say that "There is a trivial attack requiring 240 encryptions." 240 is only some 1 trillion, definitely in reach using today's computers.
Yeah, the NSA has already been doing it, you can be sure of that, and further rumors about GSM crypto that I've been hearing say that the NSA applied pressure on the French as well to insert deliberate weaknesses. Maybe Biham & Co. just managed to find out some of the NSA's "easter eggs".
Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
This isn't an issue for cell phone users in the United States. There is no encryption on your calls. So you don't have to worry about someone cracking the lame algorithm. There are secure cell phones available for GSM and CDMA networks, but they don't sell them to the proles.
Mea navis aericumbens anguillis abundat
...and as I understood it, there are two main GSM ciphers in use, A5/1 which is "strong" and A5/2 which is "weak". Both have attacks, but the one mentioned in the article which is very fast and effective is only against A5/2. The A5/1 attacks are more theoretical in that they involve known plaintext, meaning you have to guess the exact bits which were encrypted for some portion of the conversation. Plus they take enormously more work.
Apparently A5/2 is mostly used in the Middle East, including Israel. These are the people most affected by the new break. European GSM uses A5/1 which is still basically safe, it will be much cheaper to tap the landlines for those users. It is the Israelis and other A5/2 users who are toast.
Bruce Schneier mentioned how weak the GSM algorithm was back in this Dec 99 issue of Crypto-Gram. Its lousy encrpytion and is secret, non-peer reviewed.
The subject of the surveillance then makes a phone call, but you don't know what number he is using - so your warrant with the Judges signature doesn't help much.
You may observe tge phone call but you can't get an intercept because even if you know the local BSE, it may be handling 16 calls simultaneously. Under such circumstancesm off air intercepts are the only simple solution. Even then you would need to determine which conversation you wanted (GSM uses TDMA to seperate calls on a particular frequency).
I'll answer, even to an AC. #1 - it would be nice to know, but since Israel is the only nuclear state never to have signed the NPT, or agree to international monitoring of its weapons programmes, it's a little difficult. We have to rely on sources like Janes, who estimate 200-500 warheads. #2 - Israel would be exactly where it is, since none of its neighbours has the conventional capability to overcome Israels forces, with or without nuclear weapons. Egypt isn't interested, Jordan is too small, and Syria would be restricted to too small a front line to maunt an effective attack. #3 - agreed - there is no need for racism here, or anywhere. It's a question of right and wrong, not whether we like or dislike particular racial stereotypes. #4 - this is emphatically not true. Palestine was offered a very poor deal, with non-contiguous areas forming the 'state' (in reality a series of bantustans easily isolated from one another), with the loss of not 2% or 5% of the territory, as is commonly thought, but nearly 10%. Israel even proposed to keep the border area on the Jordanian side. This was not an offer that any sane man would accept. Even Barak, after the offer was declined, tried to keep the talks going, but the upcoming Israeli election (in which, worst luck, Sharon came to power) made a deal impossible. #5 - Geneva Conventions apply only to states. There is no war between Palestine and Israel, because Palestine is not yet a state. The parent attempts to apply the Geneva Conventions to a resistance struggle against occupation. The applicable Geneva Conventions are the first and fourth, covering settlement of occupied territories, collective punishment of occupied peoples and interference with medical personnel. This is not a religious struggle, no matter how you try to paint it. Israel is occupying land gained by force, and is acting illegally in settling that land and in its treatment of the local population. Just remember that the Germans viewed French resistance actions as terrorism - Israel is the invader here, and should follow international norms and law.
oh brave new world, that has such people in it!
I can't believe this has made headline news on both /. and on NewScientist... This stuff has been going for years - I have a reliable German friend who know that the German Federal Police have had this knowledge and been using it publically. A temporary base station has been used before - the privacy issue (in Germany at least) is that even with a Judge appointed warrant all calls are captured at the same time while recording one call (unfortunate kickback I'm sure).
Interesting enough but it was touted by so many as such cutting edge news...
actually Natalie thinks that arabs and israelis are cousins
"most Israelis and Palestinians are indistinguishable physically."
parent post is kinda meaningless.
CDMA, if I understand it correctly, doesn't just "hop" frequencies: it uses many frequencies simultaneously.
Each spreading code tells your phone which group of frequencies to use, and each bit of the audio stream is translated to a "chip", which is a pattern of bits on different frequencies. So when your phone broadcasts a 0 chip, it might actually send a 0 bit on frequencies X, Y, Z, and a 1 bit on frequencies A, B, C. (I'm simplifying here.. there are a lot more than 6 bits in a chip.) This is what allows for "soft handoffs" where your phone is talking to two towers at the same time: the other tower only needs to know your spreading code, it doesn't have to reserve a frequency/timeslot for you as in GSM.
Some codes use some of the same frequencies as other codes. Normally that isn't a problem, because there are enough frequencies that the tower can correct errors: if it sees a 0 on X, Y, Z, a 1 on A and B, and a 0 on C, it can decide that someone else is colliding with your C and that you really wanted to broadcast a 0 chip. A very busy cell will eventually get to a point where any extra users would cause too much interference for the phone and towers to correct those collisions, which is what causes CDMA's soft limit.
Because interference is such a key point in CDMA, the network controls everyone's broadcast power with an iron fist, to prevent users from interfering with each other or with other towers. This is useful for portable towers, among other things... the wireless carrier can put a tower in the back of a truck and park it near the stadium on Super Bowl Sunday, and the portable tower will make sure all the handsets are only using as much power as they need to reach the truck. Other towers in the area won't be overloaded by all the phone users in the stadium.
Visual IRC: Fast. Powerful. Free.
MI5 is counter-intelligence, ie operating /within/ Britain to counter security/intelligence threats. MI5 were involved in efforts to counter IRA activity, as well as tapping most phone and other comms to Rep. of Ireland.
MI6 are intelligence, ie gathering intelligence on external parties. Equivalent of the US CIA.
Apparently they've changed their names, according to another poster.
I use Friend/Foe + mod-point modifiers as a karma/reputation system.