Entries Tagged "locks"

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The Keys to the Sydney Subway

Global secrets are generally considered poor security. The problems are twofold. One, you cannot apply any granularity to the security system; someone either knows the secret or does not. And two, global secrets are brittle. They fail badly; if the secret gets out, then the bad guys have a pretty powerful secret.

This is the situation right now in Sydney, where someone stole the master key that gives access to every train in the metropolitan area, and also starts them.

Unfortunately, this isn’t a thief who got lucky. It happened twice, and it’s possible that the keys were the target:

The keys, each of which could start every train, were taken in separate robberies within hours of each other from the North Shore Line although police believed the thefts were unrelated, a RailCorp spokeswoman said.

The first incident occurred at Gordon station when the driver of an empty train was robbed of the keys by two balaclava-clad men shortly after midnight on Sunday morning.

The second theft took place at Waverton Station on Sunday night when a driver was robbed of a bag, which contained the keys, she said.

So, what can someone do with the master key to the Sydney subway? It’s more likely a criminal than a terrorist, but even so it’s definitely a serious issue:

A spokesman for RailCorp told the paper it was taking the matter “very seriously,” but would not change the locks on its trains.

Instead, as of Sunday night, it had increased security around its sidings, with more patrols by private security guards and transit officers.

The spokesman said a “range of security measures” meant a train could not be stolen, even with the keys.

I don’t know if RailCorp should change the locks. I don’t know the risk: whether that “range of security measures” only protects against train theft—an unlikely scenario, if you ask me—or other potential scenarios as well. And I don’t know how expensive it would be to change the locks.

Another problem with global secrets is that it’s expensive to recover from a security failure.

And this certainly isn’t the first time a master key fell into the wrong hands:

Mr Graham said there was no point changing any of the metropolitan railway key locks.

“We could change locks once a week but I don’t think it reduces in any way the security threat as such because there are 2000 of these particular keys on issue to operational staff across the network and that is always going to be, I think, an issue.”

A final problem with global secrets is that it’s simply too easy to lose control of them.

Moral: Don’t rely on global secrets.

Posted on September 1, 2005 at 8:06 AMView Comments

Users Disabling Security

It’s an old story: users disable a security measure because it’s annoying, allowing an attacker to bypass the measure.

A rape defendant accused in a deadly courthouse rampage was able to enter the chambers of the judge slain in the attack and hold the occupants hostage because the door was unlocked and a buzzer entry system was not activated, a sheriff’s report says.

Security doesn’t work unless the users want it to work. This is true on the personal and national scale, with or without technology.

Posted on May 2, 2005 at 8:22 AMView Comments

Security Risks of Biometrics

From the BBC:

Police in Malaysia are hunting for members of a violent gang who chopped off a car owner’s finger to get round the vehicle’s hi-tech security system.

The car, a Mercedes S-class, was protected by a fingerprint recognition system.

What interests me about this story is the interplay between attacker and defender. The defender implements a countermeasure that causes the attacker to change his tactics. Sometimes the new tactics are more harmful, and it’s not obvious whether or not the countermeasure was worth it.

I wrote about something similar in Beyond Fear (p. 113):

Someone might think: “I am worried about car theft, so I will buy an expensive security device that makes ignitions impossible to hot-wire.” That seems like a reasonable thought, but countries such as Russia, where these security devices are commonplace, have seen an increase in carjackings. A carjacking puts the driver at a much greater risk; here the security countermeasure has caused the weakest link to move from the ignition switch to the driver. Total car thefts may have declined, but drivers’ safety did, too.

Posted on April 1, 2005 at 9:12 AMView Comments

Flaw in Pin-Tumbler Locks

This paper by Barry Wels and Rop Gonggrijp describes a security flaw in pin tumbler locks. The so called “bump-key” method will open a wide range of high security locks in little time, without damaging them.

It’s about time physical locks be subjected to the same open security analysis that computer security systems have been. I would expect some major advances in technology as a result of all this work.

Posted on March 7, 2005 at 7:27 AMView Comments

Flaw in Winkhaus Blue Chip Lock

The Winkhaus Blue Chip Lock is a very popular, and expensive, 128-bit encrypted door lock. When you insert a key, there is a 128-bit challenge/response exchange between the key and the lock, and when the key is authorized it will pull a small pin down through some sort of solenoid switch. This allows you to turn the lock.

Unfortunately, it has a major security flaw. If you put a strong magnet near the lock, you can also pull this pin down, without authorization—without damage or any evidence.

The worst part is that Winkhaus is in denial about the problem, and is hoping it will just go away by itself. They’ve known about the flaw for at least six months, and have done nothing. They haven’t told any of their customers. If you ask them, they’ll say things like “it takes a very special magnet.”

From what I’ve heard, the only version that does not have this problem is the model without a built-in battery. In this model, the part with the solenoid switch is aimed on the inside instead of the outside. The internal battery is a weak spot, since you need to lift a small lid to exchange it. So this side can never face the “outside” of the door, since anyone could remove the batteries. With an external power supply you do not have this problem, since one side of the lock is pure metal.

A video demonstration is available here.

Posted on March 2, 2005 at 3:00 PMView Comments

Identity Theft out of Golf Lockers

When someone goes golfing in Japan, he’s given a locker in which to store his valuables. Generally, and at the golf course in question, these are electronic combination locks. The user selects a code himself and locks his valuables. Of course, there’s a back door—a literal one—to the lockers, in case someone forgets his unlock code. Furthermore, the back door allows the administrator of these lockers to read all the codes to all the lockers.

Here’s the scam: A group of thieves worked in conjunction with the locker administrator to open the lockers, copy the golfers’ debit cards, and replace them in their wallets and in their lockers before they were done golfing. In many cases, the golfers used the same code to lock their locker as their bank card PIN, so the thieves got those as well. Then the thieves stole a lot of money from multiple ATMs.

Several factors make this scam even worse. One, unlike the U.S., ATM cards in Japan have no limit. You can literally withdraw everything out of the account. Two, the victims don’t know anything until they find out they have no money when they use their card somewhere. Three, the victims, since they play golf at these expensive courses, are
usually very rich. And four, unlike the United States, Japanese banks do not guarantee loss due to theft.

Posted on March 1, 2005 at 9:20 AMView Comments

Hacking a Bicycle Rental System

CallABike offers bicycles to rent in several German cities. You register with the company, find a bike parked somewhere, and phone the company for an unlock key. You enter the key, use the bike, then park it wherever you want and lock it. The bike displays a code, and you phone the company once again, telling them this code. Thereafter, the bike is available for the next person to use it. You get charged for the time between unlock and lock.

Clever system.

Now read this site, from a group of hackers who claim to have changed the code in 10% of all the bikes in Berlin, which they now can use for free.

Posted on February 21, 2005 at 8:00 AMView Comments

Safecracking

Matt Blaze has written an excellent paper: “Safecracking for the computer scientist.”

It has completely pissed off the locksmithing community.

There is a reasonable debate to be had about secrecy versus full disclosure, but a lot of these comments are just mean. Blaze is not being dishonest. His results are not trivial. I believe that the physical security community has a lot to learn from the computer security community, and that the computer security community has a lot to learn from the physical security community. Blaze’s work in physical security has important lessons for computer security—and, as it turns out, physical security—notwithstanding these people’s attempt to trivialize it in their efforts to attack him.

Posted on January 14, 2005 at 8:18 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.