A lock is a mechanical or electronic fastening device that is released by a physical object (such as a key, keycard, fingerprint, RFID card, security token or coin), by supplying secret information (such as a number or letter permutation or password), by a combination thereof, or it may only be able to be opened from one side, such as a door chain.
A key is a device that is used to operate a lock (to lock or unlock it). A typical key is a small piece of metal consisting of two parts: the bit or blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. In its simplest implementation, a key operates one lock or set of locks that are keyed alike, a lock/key system where each similarly keyed lock requires the same, unique key.
The key serves as a security token for access to the locked area; locks are meant to only allow persons having the correct key to open it and gain access. In more complex mechanical lock/key systems, two different keys, one of which is known as the master key, serve to open the lock. Common metals include brass, plated brass, nickel silver, and steel. The act of opening a lock without a key is called lock picking.
Locks have been in use for over 6000 years, with one early example discovered in the ruins of Nineveh, the capital of ancient Assyria. [1] Locks such as this were developed into the Egyptian wooden pin lock, which consisted of a bolt, door fixture or attachment, and key. When the key was inserted, pins within the fixture were lifted out of drilled holes within the bolt, allowing it to move. When the key was removed, the pins fell part-way into the bolt, preventing movement. [2]
The warded lock was also present from antiquity and remains the most recognizable lock and key design in the Western world. The first all-metal locks appeared between the years 870 and 900, and are attributed to English craftsmen. [3] It is also said that the key was invented by Theodorus of Samos in the 6th century BC. [1]
'The Romans invented metal locks and keys and the system of security provided by wards.' [4]
Affluent Romans often kept their valuables in secure locked boxes within their households, and wore the keys as rings on their fingers. The practice had two benefits: It kept the key handy at all times, while signaling that the wearer was wealthy and important enough to have money and jewellery worth securing. [5]
A special type of lock, dating back to the 17th-18th century, although potentially older as similar locks date back to the 14th century, can be found in the Beguinage of the Belgian city Lier. [6] [7] These locks are most likely Gothic locks, that were decorated with foliage, often in a V-shape surrounding the keyhole. [8] They are often called drunk man's lock, as these locks were, according to certain sources, designed in such a way a person can still find the keyhole in the dark, although this might not be the case as the ornaments might have been purely aesthetic. [6] [7] In more recent times similar locks have been designed. [9] [10]
With the onset of the Industrial Revolution in the late 18th century and the concomitant development of precision engineering and component standardization, locks and keys were manufactured with increasing complexity and sophistication. [11]
The lever tumbler lock, which uses a set of levers to prevent the bolt from moving in the lock, was invented by Robert Barron in 1778. [12] His double acting lever lock required the lever to be lifted to a certain height by having a slot cut in the lever, so lifting the lever too far was as bad as not lifting the lever far enough. This type of lock is still used today. [13]
The lever tumbler lock was greatly improved by Jeremiah Chubb in 1818. [12] A burglary in Portsmouth Dockyard prompted the British Government to announce a competition to produce a lock that could be opened only with its own key. [5] Chubb developed the Chubb detector lock, which incorporated an integral security feature that could frustrate unauthorized access attempts and would indicate to the lock's owner if it had been interfered with. Chubb was awarded £100 after a trained lock-picker failed to break the lock after 3 months. [14]
In 1820, Jeremiah joined his brother Charles in starting their own lock company, Chubb. Chubb made various improvements to his lock: his 1824 improved design did not require a special regulator key to reset the lock; by 1847 his keys used six levers rather than four; and he later introduced a disc that allowed the key to pass but narrowed the field of view, hiding the levers from anybody attempting to pick the lock. [15] The Chubb brothers also received a patent for the first burglar-resisting safe and began production in 1835.
The designs of Barron and Chubb were based on the use of movable levers, but Joseph Bramah, a prolific inventor, developed an alternative method in 1784. His lock used a cylindrical key with precise notches along the surface; these moved the metal slides that impeded the turning of the bolt into an exact alignment, allowing the lock to open. The lock was at the limits of the precision manufacturing capabilities of the time and was said by its inventor to be unpickable. In the same year Bramah started the Bramah Locks company at 124 Piccadilly, and displayed the "Challenge Lock" in the window of his shop from 1790, challenging "...the artist who can make an instrument that will pick or open this lock" for the reward of £200. The challenge stood for over 67 years until, at the Great Exhibition of 1851, the American locksmith Alfred Charles Hobbs was able to open the lock and, following some argument about the circumstances under which he had opened it, was awarded the prize. Hobbs' attempt required some 51 hours, spread over 16 days.
The earliest patent for a double-acting pin tumbler lock was granted to American physician Abraham O. Stansbury in England in 1805, [16] but the modern version, still in use today, was invented by American Linus Yale Sr. in 1848. [17] This lock design used pins of varying lengths to prevent the lock from opening without the correct key. In 1861, Linus Yale Jr. was inspired by the original 1840s pin-tumbler lock designed by his father, thus inventing and patenting a smaller flat key with serrated edges as well as pins of varying lengths within the lock itself, the same design of the pin-tumbler lock which still remains in use today. [18] The modern Yale lock is essentially a more developed version of the Egyptian lock.
Despite some improvement in key design since, the majority of locks today are still variants of the designs invented by Bramah, Chubb and Yale.
A warded lock uses a set of obstructions, or wards, to prevent the lock from opening unless the correct key is inserted. The key has notches or slots that correspond to the obstructions in the lock, allowing it to rotate freely inside the lock. Warded locks are typically reserved for low-security applications as a well-designed skeleton key can successfully open a wide variety of warded locks.
The pin tumbler lock uses a set of pins to prevent the lock from opening unless the correct key is inserted. The key has a series of grooves on either side of the key's blade that limit the type of lock the key can slide into. As the key slides into the lock, the horizontal grooves on the blade align with the wards in the keyway allowing or denying entry to the cylinder. A series of pointed teeth and notches on the blade, called bittings, then allow pins to move up and down until they are in line with the shear line of the inner and outer cylinder, allowing the cylinder or cam to rotate freely and the lock to open. An additional pin called the master pin is present between the key and driver pins in locks that accept master keys, to allow the plug to rotate at multiple pin elevations.
A wafer tumbler lock is similar to the pin tumbler lock and works on a similar principle. However, unlike the pin lock (where each pin consists of two or more pieces) each wafer is a single piece. The wafer tumbler lock is often incorrectly referred to as a disc tumbler lock, which uses an entirely different mechanism. The wafer lock is relatively inexpensive to produce and is often used in automobiles and cabinetry.
The disc tumbler lock or Abloy lock is composed of slotted rotating detainer discs.
The lever tumbler lock uses a set of levers to prevent the bolt from moving in the lock. In its simplest form, lifting the tumbler above a certain height will allow the bolt to slide past. Lever locks are commonly recessed inside wooden doors or on some older forms of padlocks, including fire brigade padlocks.
A magnetic keyed lock is a locking mechanism whereby the key utilizes magnets as part of the locking and unlocking mechanism. A magnetic key would use from one to many small magnets oriented so that the North and South poles would equate to a combination to push or pull the lock's internal tumblers thus releasing the lock.
An electronic lock works by means of an electric current and is usually connected to an access control system. In addition to the pin and tumbler used in standard locks, electronic locks connect the bolt or cylinder to a motor within the door using a part called an actuator. Types of electronic locks include the following:
A keycard lock operates with a flat card of similar dimensions as a credit card. In order to open the door, one needs to successfully match the signature within the keycard.
The lock in a typical remote keyless system operates with a smart key radio transmitter. The lock typically accepts a particular valid code only once, and the smart key transmits a different rolling code every time the button is pressed. Generally the car door can be opened with either a valid code by radio transmission, or with a (non-electronic) pin tumbler key. The ignition switch may require a transponder car key to both open a pin tumbler lock and also transmit a valid code by radio transmission.
A smart lock is an electromechanics lock that gets instructions to lock and unlock the door from an authorized device using a cryptographic key and wireless protocol. Smart locks have begun to be used more commonly in residential areas, often controlled with smartphones. [19] [20] Smart locks are used in coworking spaces and offices to enable keyless office entry. [21] In addition, electronic locks cannot be picked with conventional tools.
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Locksmithing is a traditional trade, and in most countries requires completion of an apprenticeship. The level of formal education required varies from country to country, from no qualifications required at all in the UK, [22] to a simple training certificate awarded by an employer, to a full diploma from an engineering college. Locksmiths may be commercial (working out of a storefront), mobile (working out of a vehicle), institutional, or investigational (forensic locksmiths). They may specialize in one aspect of the skill, such as an automotive lock specialist, a master key system specialist or a safe technician. Many also act as security consultants, but not all security consultants have the skills and knowledge of a locksmith.[ citation needed ]
Historically, locksmiths constructed or repaired an entire lock, including its constituent parts. The rise of cheap mass production has made this less common; the vast majority of locks are repaired through like-for-like replacements, high-security safes and strongboxes being the most common exception. Many locksmiths also work on any existing door hardware, including door closers, hinges, electric strikes, and frame repairs, or service electronic locks by making keys for transponder-equipped vehicles and implementing access control systems.
Although the fitting and replacement of keys remains an important part of locksmithing, modern locksmiths are primarily involved in the installation of high quality lock-sets and the design, implementation, and management of keying and key control systems. Locksmiths are frequently required to determine the level of risk to an individual or institution and then recommend and implement appropriate combinations of equipment and policies to create a "security layer" that exceeds the reasonable gain of an intruder.[ citation needed ]
Traditional key cutting is the primary method of key duplication. It is a subtractive process named after the metalworking process of cutting, where a flat blank key is ground down to form the same shape as the template (original) key. The process roughly follows these stages:
Modern key cutting replaces the mechanical key following aspect with a process in which the original key is scanned electronically, processed by software, stored, then used to guide a cutting wheel when a key is produced. The capability to store electronic copies of the key's shape allows for key shapes to be stored for key cutting by any party that has access to the key image.
Different key cutting machines are more or less automated, using different milling or grinding equipment, and follow the design of early 20th century key duplicators.
Key duplication is available in many retail hardware stores and as a service of the specialized locksmith, though the correct key blank may not be available. More recently, online services for duplicating keys have become available.
A keyhole (or keyway) is a hole or aperture (as in a door or lock) for receiving a key. [23] Lock keyway shapes vary widely with lock manufacturer, and many manufacturers have a number of unique profiles requiring a specifically milled key blank to engage the lock's tumblers.
Keys appear in various symbols and coats of arms, the best-known being that of the Holy See: [24] derived from the phrase in Matthew 16:19 which promises Saint Peter, in Roman Catholic tradition the first pope, the Keys of Heaven. But this is by no means the only case.
Some works of art associate keys with the Greek goddess of witchcraft known as Hecate. [25]
The Palestinian key is the Palestinian collective symbol of their homes lost in the Nakba, when more than half of the population of Mandatory Palestine was expelled or fled violence in 1948 and were subsequently refused the right to return. [26] [27] [28] Since 2016, a Palestinian restaurant in Doha, Qatar, holds the Guinness World Record for the world's largest key – 2.7 tonnes and 7.8 × 3 meters. [29] [30]
Locksmithing is the work of making and defeating locks. Locksmithing is a traditional trade and in many countries requires completion of an apprenticeship. The level of formal education legally required varies from country to country from none at all, to a simple training certificate awarded by an employer, to a full diploma from an engineering college, in addition to time spent working as an apprentice.
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, also known as the Yale lock after the inventor of the modern version, is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key.
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 combination lock is a type of locking device in which a sequence of symbols, usually numbers, is used to open the lock. The sequence may be entered using a single rotating dial which interacts with several discs or cams, by using a set of several rotating discs with inscribed symbols which directly interact with the locking mechanism, or through an electronic or mechanical keypad. Types range from inexpensive three-digit luggage locks to high-security safes. Unlike ordinary padlocks, combination locks do not use keys.
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 Chubb detector lock is a lever tumbler lock with an integral security feature, a re-locking device, which frustrates unauthorised access attempts and indicates to the lock's owner that it has been interfered with. When someone tries to pick the lock or to open it using the wrong key, the lock is designed to jam in a locked state until either a special regulator key or the original key is inserted and turned in a different direction. This alerts the owner to the fact that the lock has been tampered with.
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.
A door handle or doorknob is a handle used to open or close a door. Door handles can be found on all types of doors including exterior doors of residential and commercial buildings, internal doors, cupboard doors and vehicle doors. There are many designs of door handle, depending on the appropriate use. A large number of handles, particularly for commercial and residential doors, incorporate latching or locking mechanisms or are manufactured to fit to standardised door locking or latching mechanisms.
Padlocks are portable locks usually with a shackle that may be passed through an opening to prevent use, theft, vandalism or harm.
A latch or catch is a type of mechanical fastener that joins two objects or surfaces while allowing for their regular separation. A latch typically engages another piece of hardware on the other mounting surface. Depending upon the type and design of the latch, this engaged bit of hardware may be known as a keeper or strike.
A skeleton key is a type of master key in which the serrated edge has been removed in such a way that it can open numerous locks, most commonly the warded lock. The term derives from the fact that the key has been reduced to its essential parts.
Rekeying a lock is replacing the old lock pins with new lock pins.
Lock bumping is a lock picking technique for opening a pin tumbler lock using a specially crafted bump key, rapping key or 999 key. A bump key must correspond to the target lock in order to function correctly.
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.
The term protector lock has referred to two unrelated lock designs, one invented in the 1850s by Alfred Hobbs, the other in 1874 by Theodor Kromer.
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.
Michal concedes the fact that Israelis do the same thing to the memory of the Nakba when saying "it was in 1948, enough talking about the past, let's talk about the future." When the Palestinians come with their keys [the Palestinian symbol of their lost homes], she says, "it's the same thing, it's a memory still burning in the hearts of families
Keys must always be the symbol of the Palestinian "Nakba" – the "disaster" – the final, fateful, terrible last turning in the lock of those front doors as 750,000 Arab men, women and children fled or were thrown out of their homes in what was to become the state of Israel in 1947 and 1948.
The gigantic key, dedicated to all the refugees around the world, was unveiled in a spectacular show at the Katara Amphitheatre last night featuring Palestinian Arab Idol winner Mohammed Assaf. "This key symbol for all the refugees in the world. We want to set a Guinness World Record to say that it is the right of these refugees to return back home. Actually this is linked particularly to Palestinian refugees."... Around 4,000 people filled the Katara Amphitheatre to witness the unveiling of the enormous key and enjoy the concert highlighted by the performance of the young Palestinian singer who is the first United Nations Relief and Works Agency regional youth ambassador for Palestine refugees.