AT&T Identifies Widespread Security Hole - In Locks 498
__roo writes "The New York Times has an article [free registration required] about a researcher at AT&T Labs Research who has discovered a little-known vulnerability in many locks that lets a person create a copy of the master key for an entire building by starting with any key from that building, and it requires little more than a file and a few key blanks."
i suppose that (Score:5, Funny)
"Hey steve, check out my new lock!"
"pffft, is it v.3.21.7?"
"no"
"that's like an invite for key kiddies and 1337 crackers"
Re:i suppose that (Score:4, Funny)
Re:i suppose that (Score:5, Funny)
It didn't come to attention till a spate of Office buildings found the safe hidden and the words "Ownzed by l337 b3rgl@rz!!!" spraypainted in foyers.
I believe Scotland yard are preparing a deb update.
Re:i suppose that (Score:3)
Also, I'm not sure how new this is; When I was at high school (about 20 years ago) a friend of mine managed to get hold of four or five different keys and from those he filed a 'master key' which opened about a third of the doors in our school, and he let a couple of us (me included) make a copy of it. Later the school found out, he got expelled and they changed all the locks.
Comment removed (Score:4, Informative)
Is this a joke? (Score:3, Informative)
Not that it can't be news and research for security people, but I can't see how this can "make it easier for buglers and terrorists", anyone in the business or anyone thinking about it for a few minutes knows thats how it works and have always worked, and how it has to work if you really wants a master key system.
Re:Is this a joke? (Score:3, Insightful)
Indeed. I knew it when I was ten, and I'd never even met an actual
locksmith.
The solution is equally simple: if security actually matters, you
sacrifice the convenience of having a single master key and install
locks that use a completely different key in the places that matter.
Your "master key" is then a whole ring of keys, but hey.
Next they'll start talking about how the social engineering technique
used by computer crackers can be used in the real world too...
just phone up the front desk and ask 'em to unlock the side door
and let in the plumber...
Re:Is this a joke? (Score:3, Insightful)
Re:Is this a joke? (Score:5, Insightful)
Sure, locksmiths knew this. A good sysadmin also knows the weaknesses in their systems. But as a user of both locks and ecommerce, I blindly put my trust in those systems in part because I *don't* know their weaknesses!
How many sysadmins know that the door to their server closet can be opened by an employee with a regular key?
It's like with PGP: what can you trust? Regular people know now that you cannot trust master-key systems.
Re:Is this a joke? (Score:3, Insightful)
How many sysadmins know that the door to their server closet can be opened by an employee with a regular key?
How many sysadmins keep trying to convince their bosses that security is important, only to discover that the custodial staff routinely pops in the server room to empty the trash?
Sadly, not everyone understands that security is an issue.
Re:Is this a joke? (Score:5, Informative)
The master key is usually the largest, [lysator.liu.se] not the smallest, so that people cannot file down their keys to master keys.
Re:Is this a joke? (Score:4, Informative)
Here's a pretty comprehensive article [howstuffworks.com] on lock-picking, which also explains how locks work. (After all, you can't really pick a lock without knowing what's in there).
Re:Is this a joke? (Score:4, Informative)
Matt's attack might be best described with a password analogy of a lock.
Think of a naive programmer who wrote this code:
Because that's exactly how a pin tumbler lock works.You've been given the password "FOO" for use with some ancient security system. The master password is unknown, but you know that it has three letters. The trick is knowing that there is no relationships between password letters. It will let you in regardless of if the letter was for your password or for the master password.
You start out by trying "AOO". No go. You try "BOO", and it works. Therefore, the first master letter is "B".
Next, you try "FAO". It works. Therefore, the second letter of the password is "A".
Next, you try "FOA". Nope, try "FOB". Nope, try "FOC". Nope, try "FOD". Bingo! The third letter is "D", and the master password is "BAD".
Yes, it's that easy. Instead of changing letters, you file a bit of metal off a key blank, but otherwise it's the exact same attack.
Re:here... (Score:3, Informative)
Here it is without registering for NYT (Score:5, Informative)
SOME EVEN BETER LINKS to the method itself (Score:5, Informative)
The crack works on virtually all locks and was inpsired by parallels to cryptographic analysis, reducing the search from exponential to linear, and exploiting 'key" generation weaknesses. Virtually all master-key locks are vulnerable.
There is also a story [nytimes.com] on the front page of the nytimes covering police verification of the threat including giving the instructions to a 15 year old.
HOW TO DO IT (Score:5, Informative)
1) get a normal key that opens a lock.
2)count the notches, if its a 5 pin tumbler, then buy 6 more blank keys. ($2.00)
3) cut 5 keys to be identical to the original except at one of the pin position, let it be full height. SO that you now have 5 keys each with a full height blank at a different pin postion.
3.b) reducing the complexity. it's not physically possible to have a full height position adjacent to a deeply cut position. No problem, just cut it as high a possible, the master key suffers the same limits too, and this reduces the complexity of the pattern.
4) insert the first key. does it turn? No then file off 0.010" of metal and try again. within 7 tries, usually only one or 2 it will turn. congatulation you now know the pin 1 master height.(duh: ignore the turning at the original height.)
5) insert key2, rinse, lather repeat.
the beauty of this crack twofold. first, you are discovering the master heights of each pin independently, so the combinatorics is just linear in the number of resolvable pin heights not the product of pin-positions times pin heights. Second, you are also simultaneously factoring the ordinary key out of the master key combination, thus only discovering the master key not some useless key that is part paster and part ordinary key (that would only owrk on that particular lock).
6) Exception: if you cannot find the a pin height that opens one of the tumblers (ignoring the obvious one for the original key) then the original key height is the one for the master too.
Re:HOW TO DO IT (Score:3, Insightful)
The master key does not necessarily suffer the same limits. Consider a lock where your key has a (trivial) code of 11111 (minimal cuts) and the master key has a code of 99999 (all cut to the maximum depth; I'm using Schlage codes here, just because the only key I have handy with a code stamped on it happens to be a Schlage.) In that case, none of your test keys will open the door because they will all have a 9 next to a 1 and wouldn't fit into the lock (or worse, would stick in the lock and not come back out) but neither the individual key nor the master key will have any large transitions (in fact, they won't have any transitions at all.)
I would guess that ensuring a condition like this exists is one of the suggested workarounds in the original paper.
Workaround the workaround (Score:3, Interesting)
(1) cut 6 identical keys to the original
(2) In one slot, cut as far down as possible, and drill a hole in that location, where you can put a mobile pin on a spring and a wire.
(3) drill a hole along the base, as well, and run the wire through.
(4) Now pull on the wire to find the alternate height. No filing required [prework necessary].
Just write down the numbers you get
(5) Go home and cut new key.
Also: to get around the lack of a blank:playdoh; wax; metal; plaster; small metal casting. Or digital camera; ruler; grinder; piece of small metal.
I don't take much comfort in those workarounds.
At this point, I think that digital locks with varying codes might be a tad more secure. For example, to get the day's code, the admin takes his phone number [or street address, though a random memorized number is best], adds the date to each digit and the time on the lockbox to the last 4 digits, and that's the code. Before he gets up to go in, he figures out what it will be, in his head. Of course, if he forgets entirely, he can take a blowtorch, melt the plexiglass, and let secretary out. Then call in work crews to replace the plexiglass, and stays there, meanwhile, memorizing the *new* number, and keeping an eye out for ninjas rapelling down from the roof.
Or he can write the code on his desk, the front of his pocket protector, or whatever.
Or how about this? Specialized beeper tied to lockbox, on continuous recharge. Beeper takes incoming code, checks it against security code, checks source phone number against President's code -- and authorizes computerized lockbox to open upon access key, within the next 1 minute.
Now, to go in, you pull out your cell phone, call the company president -- he pulls out his video cell phone, calls a video cell phone watching the hall; makes sure that it's you, and then calls the beeper, enters the code [encrypted, of course], and authorizes you to go in.
Of course, I'm not a cryptologist. I'll be a cryptologist could find a dozen ways to break my idea apart. After all, the more complex a system is, the more flaws it has (doesn't it?)
Re:HOW TO DO IT (Score:5, Informative)
Locate the approrpriate blank. Put it in the lock. Twist it good and hard a few times. Remove blank. Note scratches left by lock innards. Cut to match scratches. Voila, working key.
Waitaminnut... under the DMCA, isn't this reverse engineering??
Re:HOW TO DO IT (Score:4, Interesting)
Locksmithing is a closely guarded profession. They have more secrets too, but they'll be mad enough at this guy and the NYT for letting the cat out of the bag on this one.
Re:Nope, (D)MCA doesn't apply... (Score:3, Funny)
It is well-known among locksmiths (Score:4, Informative)
Bruce
I did it without the blanks (Score:3, Interesting)
For one thing, building up solder in each position makes it a lot easier to see the indentations. But the real reason this works is that if you apply a back and forth motion as your attempt to turn the key, the indentations can be made even if the other positions are not cut properly at all. So this can be done with one key, and it doesn't even have to be a blank (but it does get modified in the process, so if you can get a blank, that's better).
Not quite... (Score:4, Informative)
In particular: Medico. Their keyways (the pattern of slots on the key's side that admit it to the cylinder) in their high-security models are in a number of (copyrighted) combinations, each sold only to one locksmithing company which is under contract to only resell cut keys, keep records (with ID and passwords) of the buyers, and only sell COPIES to the legitimate owner(s) of the particular lock. The privileged smiths go along with this, too, because Medico tries to get them to violate the contract and will transfer it (along with the lucrative business) to some more picky locksmith if they do.
So unconnected people who want to try such attacks against Medico locks need to make their own blanks. But that's not hard with a model-maker's midget milling machine, of which several brands are available.
(But Medico is also less vulnerable to attacks of the sort described. The lock's pins have a wedge-shaped tip, the cut in the key is at an angle across the axis of the key, and the pin must be rotated by the proper angle as well as lifted to release.)
But most of those "do not duplicate" keys are just ordinary keys from common manufacturers, which have been stamped. The stamp relates to laws prohibiting the copying of such a key and penalizing vendors who get caught doing so.
Of course if someone sticks a label saying something like "garage" or "front door" over the stamp, most hardware store clerks won't notice the stamp and will blithely make as many copies as desired.
Re:I brute force guessed a medico in college. (Score:3, Funny)
Upgrade quickly (Score:4, Funny)
In the cert advisory, The Microsoft Corporation are quoted "Those who upgrade to Windows XP Service Pack One should be unaffected by this exploit"
Comment removed (Score:5, Funny)
In fact ... (Score:3, Funny)
PDF Download (Score:5, Informative)
Paper's homepage is here [crypto.com]
Re:PDF Download (Score:5, Funny)
Well, I think we've fixed that little problem...
Re:PDF Download (Score:4, Informative)
Mirror here [annexia.org]
Re:PDF Download (Score:4, Informative)
"Matt Blazes Paper" [iacr.org]
Re:PDF Download (Score:5, Informative)
Locks and Registration (Score:2, Insightful)
The paper itself (Score:4, Informative)
The new York Times is sketchy on the details (Score:5, Informative)
Overstating the risk? (Score:5, Insightful)
I see several problems with the article.
He said the technique could open doors worldwide for criminals and terrorists.
All in all, the article sounds more like fearmongering than a real concern.
Re:Overstating the risk? (Score:5, Insightful)
Re:Overstating the risk? (Score:3, Insightful)
For instance, let's say someone robs a house. It's obvious right away if the door is kicked in and the jamb is busted. However, if the thief is selective about what is taken (which, they never are) and also has the skills to not cause a lot of damage on the way in, then those "selective" stolen items may go unnoticed for some time, which gives the thief more time to fade into the noise.
Re:Overstating the risk? (Score:4, Interesting)
"But officer, this IS my office -- I have the key right here!!"
Re:Overstating the risk? (Score:3, Interesting)
Keep in mind that lock-picking looks suspicious and takes time at every door. This technique could be used by an insider to expand their access in a much less suspicious manner (by playing with their own office lock, for instance). It sounds like there are only 40 or 50 possible attempts to try (try, file, try, file, etc...). If that is the case, then you bring in 5 blanks to work, try them all, take them home, and do the same the next day after appropriate filing - you'd have the master in two weeks.
Also - once you have the master you have instant access to EVERY lock. Picking only opens a single lock, with some effort expended. If you want to sneak around you would want to be able to just walk through a building at will looking like you belong there.
I think this would be a technique used in corporate espionage. An agent would get a job as a janitor or some low-level job, and then get a master key to the building. They could show up in inconspicuous clothing during a different shift away from their normal work area and just waltz through the building looking like they belong. You couldn't do that with a lockpick during regular hours.
Re:Overstating the risk? (Score:4, Insightful)
Now imagine you work there, in a different suite, in some counter-terrorism capacity. Do you start looking under your car for plastic explosive, or not?
Or imagine you work elsewhere, but a colleague has an office there and keeps your name and address handy
Re:Overstating the risk? (Score:5, Insightful)
You might think so, but consider this example. There are no litter bins in British railway stations, and very few in the centre of London, like the Square Mile. This is because IRA terrorists would leave explosive in them, in order to kill or main as many noncombatants as possible. I think that clearly illustrates that a terrorist can turn the most ordinary, everyday objects into weapons. Maybe there's nothing important in the janitor's closet, but the lock is still there for a reason.
If the technique has been known to locksmiths, what makes the author think lockpickers haven't known about it, too?
True, but there's a difference between gaining a skill yourself and having step by step instructions. For example, any Chemistry graduate could make explosives from scratch, working from basic principles. However, anyone with step by step instructions could make it from everyday items, and those are the ones to worry about.
Re:Overstating the risk? (Score:4, Informative)
It must be pointed out that nowadays IRA terrorists have a habit of telling the police the general vicinity of said bombs so that civilians can be evacuated. Traffic gets snarled and countless commuters are late, but when was the last time lots of people were killed or maimed by an IRA bomb?
You must be thinking of the Basque.
Re:Overstating the risk? (Score:4, Informative)
How about the Omagh bombing [bbc.co.uk] in 1998?
29 dead. (In other words, about 1% of the September 11th attacks.)
Re:Overstating the risk? (Score:3, Interesting)
Or, for a less familiar frame of reference, 0.9% of the number of Afghan civilians directly killed by US bombs [cursor.org], not counting starvation deaths due to halted foreign aid caravans during the bombing.
I wonder if restricted keyways help (Score:5, Interesting)
I ran into this phenomenon in college; I tried to make a copy of my girlfriend's dorm room key at several hardware stores. I actually milled off and polished the head of the key where the "DO NOT COPY" and "UNIVERISTY AABBCC" info was on it so it looked like an ordinary key.
The last place I went to the guy looked at me and laughed and said, "Nice job, but its a university key -- the blanks and hardware are sold directly by to the University key shop. Even if I wanted to, I couldn't make a copy of it, I have no blanks that will work."
Anyway, the technique described here requires a bunch of blank keys, which if you can't get or are extremely hard to get makes you wonder if this technique would work in places that employ limited keyway hardware.
Re:I wonder if restricted keyways help (Score:3, Interesting)
Re:Overstating the risk? (Score:3)
I don't think this paper is going to set off a rash of burglaries and attacks, however. This method is still a lot of work given that most locks out there can be forced open with simple tools in seconds- getting regular access and then making a key is too much effort for the smash-and-grab crowd. For the doors that contain really nice stuff behind them, I'm going to guess that many are protected by more than just one lock that is part of a master key system. They may have their own key at least, and obviously for higher security doors, you're looking at the personal identification and trained men with guns approach to security, which is generally quite successful.
The venue where this becomes most applicable is probably in academia, where, for better or for worse, academic freedom tends to mean lax security. At the university physics department where I work, I have both a building entry key and a room key. I'm fairly certain that my room key is part of a master key system- if I had a master key, I would have access to the entire physics building, where a good quanitity of dangerous and expensive materials and equipment reside. Having a master would allow you access to every room in most dormitories, as well- I expect if this paper circulates on college campuses, it will no doubt lead to some hilarious pranks, but perhaps a few thefts as well.
news? (Score:4, Interesting)
Proverb (Score:4, Insightful)
Locks are against wildlife. Humans will have no problems with them.
Why does this not sound easy to me? (Score:2, Interesting)
Every time I go the cobblers to have a key cut I normally end up taking it back. The fresh key is cut on a professional key cutting machine by someone who has probably cut thousands of them - I still end up taking it back because it doesn't work in the lock. I've also worked in on the bench in an engineering company and am trained to use a file - detailed filing is not like filing your nails or removing huge burrs from machined metal.
Load of bollocks I say.
little known? (Score:5, Funny)
Yeah, until now.
Talisman
Re:little known? (Score:5, Funny)
Nice article... (Score:5, Interesting)
I find it interesting seeing that security by obfuscation is a prevalent concept throughout mankinds realm. I guess it is nurtured by the ostrich-sticking-head-in-sand effect of thinking something doesn't exist if we're not aware of it.
It also makes me laugh how newspapers always skew stuff for sensationalism: now terrorists are one step closer to the US. They are pounding on the gates! WATCH OUT!!!. I think this security whole is mostly going to be used by 16 year old K-Mart workers.
Anyways, very nice article in the end, and hats off to AT&T for having 'brass hats'.
Re:Nice article... (Score:3, Insightful)
The goal of security technology is to make something as secure as possible with the least cost possible.
All security systems rely on a secret of some sort. However, where they differ is in what has to be kept secret.
In a well-designed lock I would assert that the only thing that would have to be secret were the key itself, which I'd keep on a string around my neck at all times. If to keep things secret the workings lock mechanism itself has to be protected you have created a vulnerability. If your neighbor wants to break in they can just buy another lock of the same brand and take it apart to figure out how it works.
Secrets are very hard to protect. A password is either short and easy to guess or long and hard to remember. If you write it down then it is easier for an opponent to obtain. A good security system of any kind should avoid relying on secrets any more than necessary.
Does the bank do other stuff? YES, they have alarms, and a vault. The vault has a combination.. does that make it security through obscurity, and hence, designed by idiots?
The workings of the alarms and the vault are not secret. However, the exact alarm code and combination used by the bank are. If the alarm and vault are well-designed the knowledge of how they work should provide little benefit to a burgler. The only thing that has to be kept secret are the codes.
In the case of the master key vulnerability, simply keeping the master key well-protected affords little to no protection as long as ordinary keys are issued. The burgler needs only to know how the lock mechanism works to break it - and this is common knowledge now.
That isn't to say that new vulerabilities won't be found in existing systems, but a well-designed security system should not rely on keeping the operation of the system secret.
Shouldn't be a problem in homes (Score:2)
Since I only have one key for my whole house, they would need to get ahold of that, and if that happened I'd be screwed anyway.
Re:Shouldn't be a problem in homes (Score:5, Informative)
If this were bits rather than molecules... (Score:5, Insightful)
-S
Makes you think (Score:2)
Yeah, but have they figured out bathroom locks? (Score:2)
The builder gave me a bunch of those flat keys, so I have spares. Looks like I'll be picking up a bunch of those locks for my front and rear doors.
Fundamental problem with any master key system (Score:5, Interesting)
I had do design an encryption system to manage software options in a piece of gear I designed. I thought about having a "back-door" to enable options on any unit, the better to test software. I quickly abandoned that idea - let the master key get out, and it's game over. Sure, it may make my life slightly more difficult as a developer, but it also means that no one, not even me, can cheat the system.
When I had to write the system up for export permission, I described it in detail - algorithm, file formats, I even had to include the source code for the relevant sections. I suppose you could get that information with a FOIA request. Knock yourself out - if you don't have the private key of the keypair, you won't be able to create the options file.
Say it with me, kids - "master keys and back doors are BAD - JUST SAY NO!"
we would just tell the good guys (Score:2)
But as ever, one person's good guy is another person's bad buy.
security (Score:5, Funny)
I mean, anyone can break a window and jump right in!!
We can call that a "backdoor", and the plywood to cover them "patches".
my master key to the entire university campus (Score:5, Interesting)
The funny thing is, the lock system was not designed to have a single master key. Instead, there was supposed to be a different master key for each building. The campus wide master key was an "emergent property" of the similarities between the various building master keys. Only students possessed this master key :-)
I still have the key, but it's not so useful any more, as they've changed many of the locks.
Doug Moen
Re:my master key to the entire university campus (Score:3, Interesting)
It's possible to make a lock system with hundreds of thousands (in a 6 or 7 pin system) of "change keys" and a thousand or so "sub master keys" in one or two levels of hierarchy, and still have a "grand master" for the whole system. It may be that the campus was designed exactly that way to ensure that no "change key" could accidentally be a valid key (possibly even a "sub master") of another building. They simply would not create an actual "grand master key". But that wouldn't have prevented deriving it's code since it would be part of the design. The only way to have really avoided a grand master would have been to use a whole different blank for each building, and that might have been ruled out as too costly to stock blanks in whatever department was making the keys.
In other news... (Score:5, Funny)
Xerox PARC have issued an advisory stating that any combination lock can be "cracked" by a malicious terrorist with a finger. Due to the digital [sigh...] nature of this crime, it is now illegal to own a finger under the terms of the DMCA and patriotic Americans are being asked to remove all their fingers in a show of solidarity. U.S. President, George W. Bush, is said to be having some difficulty removing his finger from his arse. £:-)
BTW did the original story remind anyone else of the safe-cracking chapter in "Surely you're joking, Mr. Feynman"?
Great Satire! (Score:2)
Or, do I now fit in the same category with persons who posess a PhD in Nuclear Weapons?
--Mike--
MIT Guide to Lockpicking (Score:4, Interesting)
Re:MIT Guide to Lockpicking (Score:3, Funny)
The MIT guide mentions the file down master key trick, that was 1991.
With this new article I may have to try again, the last time I tried to do something with the a master key at my university I ended up matching the right pattern for the key that pulled the cylinder (used to change the lock). It was not fun to explain why my dorm lock had 'magically' come out of my door to the Office of the Physical Plant.
Lesson learned don't pick your own nose if it is exposed, err locks I mean locks.
I don't understand (Score:2)
Why would someone produce a lock for which a master key could be made anyway? Surely crimials would just steal or make a master key and they'd be laughing...
Is a master key an accidental side effect of the way a lock works, or are most locks intended to have a master key?
Nick...
Re:I don't understand (Score:3, Informative)
It's done by installing master wafers into the lock. A normal cylinder lock has pairs of pins, touching each other with a spring pushing them into the hole where you put the key. When you put the key in, the pins all line up, and the cylinder can turn, opening the lock. The length of each pin varies, in the same pattern that you see on the key. By putting in master waters you instead have 3 pins, meaning that each set has two possible positions, and therefore two different keys work in the same lock. By making the second key the same in every lock, you have a master key. The master key for each building or complex would be different, so there is no universal master key.
Adding master wafers increases the cost of the lock, so it's only done when the lock is going to be used in a master key situation.
This is clearly illegal! (Score:5, Funny)
Re:This is clearly illegal! (Score:3, Interesting)
So it finally happened, eh? Damn I'm curious now (Score:5, Insightful)
Foo: Why should we disclose computer security vulnerabilities when we don't disclose, say, lock vulnerabilities?
Bar: Because if a way to break a common lock would be disclosed 1. it would be very difficult to "issue a patch," or upgrade the locks 2. it would be very expensive to "issue a patch," or upgrade the locks 3. locating and telling all people who use the lock that the security of that lock has been compromised would be nearly impossible, or at least much more difficult than in the equivalent computerized situation. Therefore it seems it is not worthwhile going public with a lock vulnerability, but from this it does not follow that one shouldn't disclose computer security vulnerabilities.
If this line of reasoning is one that computer security full disclosure advocates finds compelling, and I think it is, one would expect them to condemn the disclosure of this vulnerability. Note the "would" in that sentence.
I'm not sayin', I'm just sayin'...
Cant wait for bluetoof (Score:4, Insightful)
Among all the other cool data sync things I think bluetooth enables, the death of keys is the other cool thing I really want bluetooth for.
Re:Cant wait for bluetoof (Score:5, Insightful)
Schlage to Invoke DMCA (Score:4, Funny)
Too little concern for physical security.... (Score:5, Interesting)
Ok, there are a lot of replies here that seem to be saying that physical security, especially regarding locks, is not that important. You would be surprised.
Let's look at places that have master keyed systems:
So, it shouldn't be taken lightly that many master key systems are vulnerable to attack.
You can talk about your electronic lock systems all day, but most (at least in the UK) have a normal lock as part of them, with the electronic system for convenience and being able to tell who is where and when. If they don't have a normal lock in them, then they quite often have fire crash bars on the other side.
I haven't had a chance to read the paper yet, as the crypto.com site is slashdotted, as is the mirror I found. However, a lot of master key systems have vulnerabilities. For example:
Some keys have ridges down the sides. Sub master keys only differ from master keys in that they have these ridges, preventing them from being used in other parts of the building. File off the the ridges, and off you go.
Get two or more keys from a mastered building. Notice similarities and differences. It is often very easy to deduce the master key from this, because often the mastering works by pins having several splits in them.
These are extremely simple ways of finding masters. There is of course the fact that keys are often badly controlled, and unlike passwords, are not easy to change from a central location.
Security through obscurity is often a method used with locks. And it works reasonably well. I would say that lock picking is a far rarer skill than being able to use a computer well.
Some of the more recent lock systems (Assa, Schlage etc.) are very hard to copy, sometimes involving three separate mechanisms in the lock which all need to work. This is if you can obtain blanks. Some even involve small magnets. They are hard, if not impossible to pick as well.
More worrying, however, is the lack of physical strength in most doors. If you aren't afraid of leaving traces, opening most doors by force is remarkably easy. Yale locks (front door latches) often only take one kick to open. Even mortice locks are often badly installed and not that strong. Even if the lock holds up, the door, most of the time, won't hold up to a crowbar, or in desperate situations, an electric saw of any kind.
So, although I am sure that the technique presented in the paper has been around for years, it's going public big time now. We're going to have to welcome the script kiddies who practise on the real world soon.
I have a solution... (Score:3, Interesting)
Kevin Again? (Score:3, Funny)
No need to "Free Kevin" anymore... he's got the master key!
"No, Officer, I didn't steal the key to the prison, I didn't take any hostages, all I had to do to get out was use this file here that Randall sent me in a Perl 6.0 Birthday Cake..."
I Financed my University Education that way.. (Score:4, Informative)
For centuries, locksmithing has been a sort of "black art" and the inner workings of them kept under tight control. But that only goes so far, as we all know from the Crypto industry.
Locks are, in fact, absurdly easy to open if you know what you're doing. If you've got one key to a lock that is master keyed, you can easily figure out what the master key looks like. Without that initial key, it's only slightly more problematic.
And don't think safes are any safer. Except for those that are specifically designed to thwart attack, most safes are designed to protect documents from fire and environmental hazards. They are not designed to keep intruders out. For those types of safes, anybody with a heavy hammer and a metal punch can open it. You'd be surprised how many people are stupid enough to put cash and valuables in them. In high schools, the combination padlocks on school lockers can easily be opened with a screw driver.
As the old saying goes, locks are meant to prevent honest people from being tempted. The crooks don't care.
I studied locks in depth when I was in high school and put that knowledge to good use when I needed quick cash as a starving student in university.
Needless to say, I'm posting this anonymously.
I did this 30 years ago in college (Score:5, Interesting)
This is not an unknown technique. I did this 30 years ago in college. And I only made adaptations to the technique described in a book on locksmithing which was checked out of the college library. I just didn't have any blanks to work with so I made do with one lost key I found. The campus used a type of blank not sold to the public.
A grand master keying system is based on 5 to 8, but usually 6, tumblers, with typically 10 levels or codes for each tumbler. A simple master system will have at least 2 tumbers with double cuts (but the doubles cannot be cut too close). A more complex system with a level of submastering will have 4 tumblers double cut. A grand master system with potentially two or more levels of submastering will have all the tumblers double cut.
Presuming it is a grand master system (and very large numbers of change keys generally are made this way even if no grand master key is produced), then you can presume that each position on the key is different between your key and the grand master. And not only is it different, but you can also rule out the level which is one above or below what your key has (the tumbler piece would be prone to pivot and jam, instead of slide, if cut too close). And even two levels apart is often avoided because a tumbler piece of those length can jam, although they insert a ball if the tumbler width is the same as 2 levels in that position (or 3 in some systems).
So for a typical 6 tumbler 10 level system, you can rule out 3 levels (or 2 if your key is at the highest or lowest) at each position, and the levels 2 above and below are less likely (try them last).
From your key, you can figure out about where all the levels are. Any additional keys (and I had one, and since this is a non-destructive step, I could also look at a friends' keys) can help. Now with the one spare key I had (extras help a little), you begin the step to find the master levels.
When a key position is ground just a little bit too high, usually about 1/4 of a level interval, it can still engage the tumbler cuts, but it will be rough when doing so. The same thing happens when it's low, but that's not helpful, so make the cut a little high. Even if the other positions are wrong this can be done, but if they are right it's easier. Putting a bit of solder on the position to raise it really helps because now you can see an indentation formed due to the pressure. Attempting to turn the key in the lock will try to work in those positions just a bit off, but will leave a mark on the key, especially if the metal is soft like solder. If there is no indent, you didn't get the right level, so try another at that position.
Repeat for all positions. If you are good you can even work all positions in parallel and accomplish this in just minutes. Once you have a level for every position which is at a different height than your own key, you probably have the grand master. If your key was really a submaster, this could trip you up. But they generally try to avoid giving out submaster keys to students.
There are two other ways to do this.
You can remove the lock and pull the tumblers and measure them. Be very careful because when you tap out the slide to expose the tumblers, do so one at a time because there's always a spring on top to keep the tumblers under pressure. Of course don't lose the parts, and don't lose the order the tumbler pieces come out. Now you can simply see what levels for each position make up the grand master.
Another method is to figure out all the levels and their distances. The micrometer caliper helps here. Write down the levels for your key. The next step is to examine other keys of other students. Of course they will think you're trying to make a copy of their key, but if they're your friends and you can trust them, you can reveal your real plan. Write down the levels for their key as well. This now lets you rule out some more levels at each position which the master cannot be. With enough keys you can narrow down just what the grand master key is.
If all the keys you examine are part of the same submaster system, you'll notice that 2 or 3 or maybe 4 positions are just the same on all keys. The grand master will be different there, but if you just cut your new master key at those levels anyway, while you won't have a grand master, you will end up with a submaster which can be used on all the locks in area (usually a building or so) that the examined keys came from.
A combination of having a few change keys (yours and a few friends' keys) to rule out more levels in some positions, and working with the first method to find the master levels, can speed things up for you.
Like I said before, I didn't actually invent these methods; I read them from a locksmithing book. I merely adapted the solder techniques to make things a little easier. Real locksmiths can do it without solder.
Oh, one more thing... (Score:5, Insightful)
Oh, one more thing. If you do decide to make yourself a grand master key, and are tempted to carry it around on your key ring, cut the hilt off so that the key will go in too far to work. Then only you will know that you have to put it in only part way. So if you get stopped and someone thinks you might have a master key and tries the keys on your ring, their natural human thing of "go all the way" will prevent them from detecting that your key works the lock.
Re:Oh, one more thing... (Score:3, Funny)
This is still too dangerous, since they can see that you cut off the hilt and they can just compare your key to theirs (if they have a master of their own.)
Much better to cut the key backwards -- that is, the cut normally at the end appears next to the hilt, etc. Unless the master is symmetrical, they won't be able to compare it to theirs, and it won't work when they try it.
Of course, you'll have to insert it from the back of the lock to use it, but that's a minor inconvenience compared to prison time.
And now for the secure solution (Score:4, Informative)
And now for the secure solution. You're gonna like this [keso.com] (in German).
"Good Guys" vs "Bad Guys" (Score:5, Insightful)
The writer speaks of the familiar dilemma of whether to publish to the "Good Guys," which notifies the "Bad Guys" simultaneously, or keep the information secret, knowing the "Bad Guys" could be sharing it already. Same old story we know from cyber security.
Then there's the "Locksmith" angle, "We've been teaching our students this for years, nothing new here." One wonders how the teachers sorted the trustworthy students from the evil students.
Good guys, bad guys, locksmiths, students, trustworthy, evil.
The enormous elephant here is whether people and their motives can be categorized this way. The truth is, these categories aren't cut and dried distinctions.
Take your government agent, for instance. When we're thinking about wiretapping mad bombers, they look more like good guys. When we're thinking about wiretapping political dissidents, they're bad guys. Same people, same behaviors, different categories.
Even discussing the distinction brings up more fuzzy categories: "bombers," "dissidents," "we."
As long as security is addressed from a good-guys vs bad-guys distinction, the argument will go in circles, because you can't really sort out the good guys from the bad guys without a clear value context. If you're diligent, you'll get mired in the values debate, and if you're not, you'll end up drawing biased conclusions.
The best stragegy in the good guys vs. bad guys debate is not to play the game.
When making powerful tools like locks, master keys, and cryptography, you have to bite the bullet that you can't really manage the motives of the tool users.
As long as you can get the blank keys, yes .. (Score:3, Funny)
The method as described on other comments, is just brilliant.. But there is one problem that nobody has mentioned..
How do you get the blanks ?
You see, with master-key systems the keys have other shapes than ordinary keys (often a mirror pattern if you look at the end of the key, so ordinary keys won't fit in master locks) Keys in master-key systems are often also a little longer than ordinary keys.
And Joe sixpack just can't walk into any hardware store and ask for the blanks.. The hardware store has limited numbers (if any at all) and has to get the paper-certificate that was delivered with the key-system, before they will cut you a new copy.
And, no, just bringing the master key to them and asking for a copy doesn't work (I already tried that ;-)
Complications (Score:5, Informative)
1) interchangeable core locks (Falcon or Best types). In addition to having master pins for the master key, there will be additional pins for the alternate shear line for pulling the cylinder out. Basically, if you find another key cut that works, you don't know if you have found the master key or the cylinder removal key cut.
2) MK? GMK? GGMK? Some key systems have multiple levels of keying. Though a well-designed system won't have too many stacked master pins, you still will likely end up finding a cut that works and not knowing if it's for the Master Key, Grand Master Key, Great-Grand Master Key, etc. Depending on the "resolution" of the key system, you could end up with a sub-master that only opens (say) five doors.
3) restricted keyways. Medeco, Assa, Schlage, et. al offer numerous restricted keyways. Good like finding blanks.
4) maximum adjacent cut differential. A Schlage key, for example, can have a depth from 0-9 on any given cut, but no two cuts that differ by more than 7 can be next to each other. If your office key is cut to 99333, and the master key is 51133, then one of the keys you'd have to cut using this system is 91333. A nine and a one are over the max differential, which would either obliterate the "1" cut, or the angle between them would be too steep-- in which case, good luck pulling this key out again.
Nothing new, totally obvious. (Score:3, Interesting)
The dorm management did discover it eventually. I didn't use it for anything but a little urban exploration, but I think I let a few too many people back into their rooms after their roommates locked them out and the RA wasn't around, and it became common knowledge that I had the key.
They asked how I found out how to make master keys, but didn't seem to be too convinced when I just said "Well, it's obvious, isn't it? Just think for a minute and anyone could figure it out." Probably the wrong thing to say to someone who was probably a humanities major.
My knowledge came exclusively from the Junior Worldbook Encyclopedia entry on how locks work, plus about 2 minutes of thinking about it.
Their Fix, Having RTFA: (Score:3, Insightful)
What they don't say, but is easily calculated, is that you can raise the security of each individual lock by increasing the number of pins.
Specifically: if you have a single master key, then you have to go up from double-cut up to triple-cut. That means that I'll work with log-base-3 below (for triple cut).
In that case, the number P of additional pins you must add, having formerly had N pins, and having x (let us suppose 9) possible cut heights, then
P = N/[Log3(x)-1]
So if you have 9 possible heights for each pin, single master key, and 5 tumblers, then you can prevent privelege escalation with no further loss in security by going to 5+[5/(2-1)]=10 pins. Not common today, but not impossible. Currently most locks run from 5 pins to 8 pins. Add two pins to an 8 pin lock, and you get your 10 pin security, privilege-protected.
Or you can go open source.
Damn (Score:3, Interesting)
I've known about the flaw in the master key system for a long long time.
Actually, in many circumstances you can get by the mechanism by continually retrying and wiggling your key until the fit hits.
Its not guranteed, but its a little better then using a file.
Read the "MIT Guide To Lock Picking" (Score:3, Insightful)
And specifically read section 9.10 about Master Keys. This stuff is pretty old and well circulated. The entire guide makes for a great read if you're bored. If you're interested in mind teasers, puzzles, and such, you'll appreciate what the guide talks about, even if you never attempt to pick a lock.
Re:I'm locked out of the article.. (Score:2, Funny)
Re:Where's the DMCA when you really need it? (Score:2)
Hey, they would even sue you if you just made a few copies for personal use! Eg. to give your girlfriend access to your home.
Re:Where's the DMCA when you really need it? (Score:4, Interesting)
It is interesting that nobody really thinks that keeping this secret, or making it illegal to investigate would improve security in buildings, but somehome it makes sense for digital media.
Re:This is dumb (Score:2)
Re:This is dumb (Score:2, Informative)
It is different because the method can be used to create a Master Key to an entire building (like every single door in a block of flats for instance) from a key that only opens one single door in the same building.
If you make a copy of the single key, you only get to open the single door.
Re:I have been doing it all wrong!!! (Score:3, Funny)
Well as en evil overlord you should know that it's always preferable to get the key to the restroom, make a master key, and then copy the plans of the good guys without them ever knowing
You break down the door and steal the plans: they change the plans and install stronger door. That's a vicious circle
You make a master key and steal their plan, they know nothing, plan stays the same, locks stays the same. You screw their plan over without letting on you know it, then next week when they have a new plan you go get that too.
pff evil overlords these days, no respect for finesse. You should be EvlUndrLrd instead
And no Occams razor doesn't apply, "Out of two possible explanations the simplest one is most likely to be true". You seem to be thinking along the lines of "Out of two methods of breaking and entering, the simplest one has to be better" which may not be true depending on the situation
Compare the time it takes to make a master key and enter 100 rooms to the time to break down 100 doors