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TSA Master Keys

schneier.com

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Re: TSA Master Keys

#71

Post by gozo »

hyperpape wrote: post #53
brk wrote: post #5

I doubt these images really did all that much for people who wanted a set of TSA keys. The locks themselves are widely available and it's easy to reverse engineer a key if you have the lock (especially multiple copies of the lock to destroy and test on). If anything, this just made it easier for casual lazy people to get a set of images for keys they'll never make :)

It seems like the real value of the picture was that it made it obvious how insecure the system was.

The tiny locks and keys kind of make it obvious that it's not so much insecure as it was never ment to be secure.

Re: TSA Master Keys

#72

Post by mikeash »

flavor8 wrote: post #11
tempodox wrote: post #6

Not only is this another impressive demonstration of incompetence, but by disseminating the idea that people's luggage could be “secure” and “backdoored” at the same time, they're actually destroying what security has existed before. They should pivot to be the “Transport Endangerment Agency”.

Most luggage isn't really secure in the first place. It takes less time to open up a suitcase with a good knife than it does to unzip many suitcases. The idea that a little padlock will protect your suitcase from thieves is laughable. Like physical mail, the system is based on trust, and trying to patch security onto it is difficult.

Padlocks protect you from baggage handlers getting a little on the side while on the job. If a baggage handler slices your bag open with a knife, that's going to be noticed quickly, and the odds of being caught are high. If the bag is unlocked and he can merely unzip it, pocket something valuable, and replace it, then that may not be discovered for many hours or even days, and the odds of being caught are much lower.

Obviously they don't protect you from someone who simply steals your entire bag, to open it at leisure away from the airport. But something doesn't have to protect against every conceivable threat in order to be useful.

Locks on your luggage is like locks on your front door. A lock on a normal house door is easily defeated with a crow bar or a strong leg. But they're still useful to keep out people who are willing to use the door knob but not actually break down the door.

Re: TSA Master Keys

#73

Post by mrjones »

tptacek wrote: post #52
kabdib wrote: post #38

Earlier quoted context omitted.

This. One thing that kills escrow systems dead is the complacent spread of authority. You start with critical keys that are closely held. Over time other parties express the need for access ("Okay, if you promise to be good"). Nothing bad happens (that anyone can prove...) so over time more entities are brought into the circle of trust. Eventually the dog-catcher has access to your stuff. There's no way these keys ha…

I'm asking a different question. Forget about leaks for a second. If a mechanical engineer can get their hands on 1,000 sample locks and keys (for instance: by simply buying them) and then imaging them, is it that difficult to reverse engineer the skeleton key system?

Matt Blaze developed a very cool attack against master-key lock systems: http://www.crypto.com/papers/mk.pdf

It requires access to one (non-master) key as well as a lock which is open-able by that key. It also requires being able to generate a modest number of new keys with a key cutter (however significantly fewer than brute forcing the entire space).

IIRC, the attack boils down to: - Start with the known non-master key - Hold all but one of the teeth constant, and try different values of that one tooth until you get a different working key. This other value must be the master key's value. - Repeat until you have the master value for each tooth.

If TSA locks work the same way as the locks described in this paper, a single lock/key seems sufficient to generate the master key.

Re: TSA Master Keys

#74

Post by scurvy »

coldpie wrote: post #22
harkyns_castle wrote: post #2

Seems to still be a lot being done in the name of security theater in the US, and just wasting dollars on the TSA, for what appears to be very little effect. Who's really profiting there? Is it just for the employment of people that otherwise wouldn't have a job? Or are the majority of citizens there really made to feel more secure by having them? I'd have to say some defense contractor is getting a bit fatter off th…

> Seems like a ridiculous waste of money. The people paying for it (US citizens and those who travel into or through the US) would surely see it as a waste. But the people profiting don't, and the people profiting are the same people who make the laws mandating them. I opt out of the naked scanners every time I fly. Just tell the TSA clown trying to herd you into the naked scanner the magic phrase "I'm opting out." A…

I always opt out of the "rapey-scan", then smile and groan a little whenever they pat me down. I also travel about 30-40 segments a year, so I get my kicks frequently. It's surprising how often that "TSA Precheck is closed" or the TSA Pre metal detector beeps just for me.

Re: TSA Master Keys

#75

Post by mikeash »

kitd wrote: post #63
brk wrote: post #5

I doubt these images really did all that much for people who wanted a set of TSA keys. The locks themselves are widely available and it's easy to reverse engineer a key if you have the lock (especially multiple copies of the lock to destroy and test on). If anything, this just made it easier for casual lazy people to get a set of images for keys they'll never make :)

Can you reverse engineer a master key from one sample lock though? Genuine question, IDK.

Should be doable as long as you have the non-master key for that lock too. A standard key lock works by having pins which are separated into two pieces. The key lines up the boundaries with the cylinder, which allows the cylinder to turn. Master key systems are typically done by having the pins be separated into three pieces, which allows two positions to turn the cylinder. One position is used by the normal key, and one is used by the master key. Having the normal key will let you figure out which is which, and then you can figure out the master key from that.

Re: TSA Master Keys

#76

Post by gmaslov »

kitd wrote: post #63
brk wrote: post #5

I doubt these images really did all that much for people who wanted a set of TSA keys. The locks themselves are widely available and it's easy to reverse engineer a key if you have the lock (especially multiple copies of the lock to destroy and test on). If anything, this just made it easier for casual lazy people to get a set of images for keys they'll never make :)

Can you reverse engineer a master key from one sample lock though? Genuine question, IDK.

The way I understand master keys work is that the lock has two "breaks" in each pin, instead of just one. So each pin has two positions that allow the lock to open, and you don't know which one belongs to the master key.

I think at least two locks would be required, and depending on how many pins and possible positions there are, more might be needed in case of a collision.

Re: TSA Master Keys

#77

Post by harkyns_castle »

Jtsummers wrote: post #35
harkyns_castle wrote: post #15

Earlier quoted context omitted.

It's bizarre it can happen. Surely the wheels have to fall off that out of control cart soon.

You'd think, but year after year we get stories like this. Sometimes it catches up with people [1], many times it seems they get away with it [2]. The main difference seems to be how much money they're worth, if they're elected or just "regular" employees, and how good their connections are. [1] https://en.wikipedia.org/wiki/Darleen_Druyun [2] http://www.forbes.com/sites/judystone/2015/02/17/the-sham-of... - goes int…

It sucks to watch corruption and violence win the day. We seem to be seeing it. Where an economy can be based on maintaining a military force in other countries, to maintain the petrodollar and central banks. And a lot of good people losing their lives, brought up in the belief, they're helping freedom. What a mindfuck that is.

Re: TSA Master Keys

#78

Post by mikeash »

rogeryu wrote: post #23

So luggage handlers can open my suitcase, put in some drugs, and at the other end I can get caught for having drugs in my luggage? They should setup a service where you checkin your luggage, they check it for drugs or illegal stuff, they seal it, and at arrival you get your suitcase with the guarantee that it had no drugs at checkin.

Just bring your own drugs. What are the odds of two people putting drugs in the same suitcase?

Re: TSA Master Keys

#79

Post by explorigin »

Vexs wrote: post #59

I'm kinda surprised that key number 2 on the imgur mirror is a dimple lock. Those are generally used for more high security things than crap tsa travel locks; they're expensive too. Key 4 doesn't surprise me though. https://imgur.com/a/JQD7l

Dimple locks are not at all for high-security, they are less common though.

They can easily be defeated with a deep-drilled blank wrapped in aluminum foil.

Re: TSA Master Keys

#80

Post by jsprogrammer »

chrisBob wrote: post #62
flavor8 wrote: post #11

Earlier quoted context omitted.

Most luggage isn't really secure in the first place. It takes less time to open up a suitcase with a good knife than it does to unzip many suitcases. The idea that a little padlock will protect your suitcase from thieves is laughable. Like physical mail, the system is based on trust, and trying to patch security onto it is difficult.

His suggestion about seals is the most valid point. None of the locks are really locks. A TSA compliant lock that records the time when it was opened might be useful, but otherwise a seal provides a lot more value. The zip tie idea is fine except that my checked bag is the only place I can put something capable of cutting one.

I'd argue the seal provides little value as the TSA will need to break it if they wish to search the luggage. Once the seal is broken, the luggage may be tampered with. Perhaps if the TSA resealed the luggage they searched?
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