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Lock bumping is a lock picking technique for opening a pin tumbler lock using a specially crafted bump key, rapping key or 999 key. [1] A bump key must correspond to the target lock in order to function correctly. [2]
A US patent first appears in 1928 by H. R. Simpson called a rapping key. [3] In the 1970s, locksmiths in Denmark shared a technique for knocking on a lock cylinder while applying slight pressure to the back of the lock plug. When the pins would jump inside of the cylinder, the plug would be able to slide out freely, thus enabling the locksmith to disassemble the lock quickly. [4] The use of a bump key was not introduced until some time later and was first recognized as a potential security problem around 2002–2003 by Klaus Noch, who brought it to the attention of the German media. [5] After further examination of the procedure, a white paper was drafted in 2005 by Barry Wels & Rop Gonggrijp of The Open Organization Of Lockpickers (TOOOL) detailing the method and its applicability. [6] A patent exists for a lock device following the same principle as the bump key from 1926–1928.
Marc Tobias, an American security expert, began to talk publicly in the United States about the technique and its potential security threats. In 2006, he released two further white papers regarding the technique and its potential legal ramifications. [4]
A pin tumbler lock is composed of a series of spring-loaded stacks called pin stacks. Each pin stack is composed of two pins that are stacked on top of each other: the key pin, which touches the key when it is inserted, and the driver pin, which is spring driven. When the different length key pins are aligned at their tops by the insertion of the correspondingly cut key at their bases, the tops of the key pins and, consequently, the bases of the driver pins, form a shear line, so that the cylinder can be turned, rotating the key pins away from the driver pins. When no key or the wrong key is in the lock, pin misalignment prevents the cylinder from turning. [7] [8]
To bump a lock, a person inserts a bump key into the key way one notch (pin) short of full insertion, then bumps the key inward to push it deeper into the key way. The specially designed teeth of the bump key transmit a slight impact to all of the key pins in the lock. The key pins transmit this force to the driver pins; the key pins stay in place. [9] This is the same physical phenomenon seen in the desktop toy Newton's cradle. Because the pin movements are highly elastic, the driver pins "jump" from the key pins for a fraction of a second, moving above the cylinder (shear line of the tumbler), then are pushed back by the spring. With no other forces applied, the driver pins would come back to rest against the key pins once again, but the person applies a light rotational force to the key during the process and this causes the cylinder to turn during the short time that the driver pins are above the shear line, thus opening the lock. Lock bumping takes only an instant to open the lock. The lock is not visibly damaged, although the force of the bump can leave an indentation on the front of the cylinder. Certain clicking and vibrating tools designed for bumping can also be used. These allow for rapid repetition of bumping. Though some locks have advertised "bump proof" features, only a rare few key-pin locks cannot be bumped.
A different tool with a similar principle of operation is a pick gun. [3]
Lock bumping is a trend in burglaries, [10] [11] as the technique can make it easy and fast to break into homes without needing too much special equipment or leaving any trace of forced entry. It works almost as well as having a key, [12] [13] and a set of ten rapping keys can make the criminals capable of opening 90% of common tumbler locks.[ citation needed ]
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High-quality locks may be more vulnerable to bumping unless they employ specific countermeasures. More precise manufacturing tolerances within the cylinder make bumping easier because the mechanical tolerances of the lock are smaller, which means there is less loss of force in other directions and mostly pins move more freely and smoothly. Locks made of hardened steel are more vulnerable because they are less prone to damage during the bumping process that might cause a cheaper lock to jam.
In the United Kingdom, a British standard TS007 Kitemark has been legislated which benchmarks the effectiveness of bumping at 1-star level and 3-star level. The former implies a minimum bump time of 1 minute while the latter offers much greater protection at a minimum bump time of 10 minutes. [14]
Security pins (e.g. spool or mushroom pins)—even when combined with a regular tumbler mechanism—generally make bumping somewhat more difficult but not impossible.
Because a bump key must only have the same blank profile as the lock it is made to open, restricted or registered key profiles are not any safer from bumping. While the correct key blanks cannot be obtained legally without permission or registration with relevant locksmith associations, regular keys can be filed down to act as bump keys.
Trap pins that engage when a pin does not support them will jam a lock's cylinder.
Another countermeasure is shallow drilling, in which one or more of the pin stacks is drilled slightly shallower than the others. If an attempt is made on a lock that has shallow-drilled pin stacks, the bump key will be unable to bump the shallow-drilled pins because they are too high for the bump key to engage.
Locks that only use programmable side bars and not top pins are bump-proof. BiLock is an example of this technology. Many bump-resistant locks are available which cannot be easily opened through the lock bumping method.
Time locks, combination locks, electronic locks, electromagnetic locks, and locks using rotating disks, such as disc tumbler locks, are inherently invulnerable to this attack, since their mechanism does not contain springs. However, some electronic locks feature a key backup that is susceptible to bumping. Warded locks are not vulnerable to bumping, but they are vulnerable to a similar attack called a skeleton key, which is also a filed-down key.
Changing the spring tension can help reduce bumping. A few sources inside the industry offer stronger top springs for conventional pinned locks. Changing one or two top springs to a firmer spring changes the ricochet tuning of the top pins, making it hard to bump.
Lock picking is the practice of unlocking a lock by manipulating the components of the lock device without the original key.
A warded lock is a type of lock that uses a set of obstructions, or wards, to prevent the lock from opening unless the correct key is inserted. The correct key has notches or slots corresponding to the obstructions in the lock, allowing it to rotate freely inside the lock.
The pin tumbler lock is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key. Pin tumblers are most commonly employed in cylinder locks, but may also be found in tubular pin tumbler locks.
A disc tumbler or disc detainer lock is a lock composed of slotted rotating detainer discs. The lock was invented by Finnish founder of Abloy, Emil Henriksson (1886–1959) in 1907 and first manufactured under the Abloy brand in 1918.
A tubular pin tumbler lock, also known as a circle pin tumbler lock, radial lock, or the trademark Ace lock popularized by manufacturer Chicago Lock Company since 1933, is a variety of pin tumbler lock in which a number of pins are arranged in a circular pattern, and the corresponding key is tubular or cylindrical in shape. Most locks use between six and eight pins, although some use as few as four or as many as ten. The devices have been widely used on vending machines, elevators, public computers, and bicycle locks.
A lock is a mechanical or electronic fastening device that is released by a physical object, by supplying secret information, by a combination thereof, or it may only be able to be opened from one side, such as a door chain.
A lever tumbler lock is a type of lock that uses a set of levers to prevent the bolt from moving in the lock. In the simplest form of these, lifting the tumbler above a certain height will allow the bolt to slide past.
A mortise lock is a lock that requires a pocket—the mortise—to be cut into the edge of the door or piece of furniture into which the lock is to be fitted. In most parts of the world, mortise locks are found on older buildings constructed before the advent of bored cylindrical locks, but they have recently become more common in commercial and upmarket residential construction in the United States. The design is widely used in domestic properties of all vintages in Europe.
Safe-cracking is the process of opening a safe without either the combination or the key.
Padlocks are portable locks usually with a shackle that may be passed through an opening to prevent use, theft, vandalism or harm.
Medeco, a subsidiary of the Swedish Assa Abloy Group, is a lock manufacturer located in Roanoke County, Virginia, United States.
Rekeying a lock is replacing the old lock pins with new lock pins.
A master key operates a set of several locks. Usually, there is nothing special about the key itself, but rather the locks into which it will fit. These master-keyed locks are configured to operate with two, or more, different keys: one specific to each lock, which cannot operate any of the others in the set, and the master key, which operates all the locks in the set. Locks that have master keys have a second set of the mechanism used to operate them that is identical to all of the others in the set of locks. For example, master keyed pin tumbler locks often have two shear points at each pin position, one for the change key and one for the master key. A far more secure system has two cylinders in each lock, one for the change key and one for the master key.
A wafer tumbler lock is a type of lock that uses a set of flat wafers to prevent the lock from opening unless the correct key is inserted. This type of lock is similar to the pin tumbler lock and works on a similar principle. However, unlike the pin tumbler lock, where each pin consists of two or more pieces, each wafer in the lock is a single piece. The wafer tumbler lock is often incorrectly referred to as a disc tumbler lock, which uses an entirely different mechanism.
A snap gun, also known as lock pick gun, pick gun, or electric lock pick, is a tool that can be used to open a mechanical pin tumbler lock without using the key. A thin steel blade, similar in shape to a lock pick, is inserted into the lock and the snap gun briefly fires the blade against all of the lock pins simultaneously, momentarily freeing the cylinder and enabling it to be turned using a tension wrench. The snap gun is an alternative to a conventional lockpick, which requires other techniques such as raking to free the pins.
Bilock is a high-security keying system designed and manufactured by Australian Lock Company. It is advertised to be bump-proof, pick-resistant, and drill-resistant. The Bilock cylinder uses a patented locking system with two sidebars, 12 pins, and 12 springs. In the New Generation Bilock, a trigger pin has been added to increase security and extend the registered design of the product. The key design is a U-shape profile with six cuts on each side of the key, along with a central roller to activate the trigger pin in the front and center of the cylinder.
The Open Organisation of Lockpickers or TOOOL is an organization of individuals who partake in the hobby of locksport, as well as educate its members and the public about the security provided by common locks.
A magnetic keyed lock or magnetic-coded lock is a locking mechanism whereby the key utilizes magnets as part of the locking and unlocking mechanism. Magnetic-coded locks encompass knob locks, cylinder locks, lever locks, and deadbolt locks as well as applications in other security devices.
The Bramah lock was created by Joseph Bramah in 1784. The lock employed the first known high-security design.
This is a glossary of locksmithing terms.
| Fundamental concepts |  | |
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| Components and hardware | ||
| Keys | ||
| Mechanical locks | ||
| Electronic locks | ||
| Other lock types | ||
| Lock picking | ||
| Security alarms |
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| Miscellaneous | ||
