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The Different Types of Keys & Key Blanks
A
key is a device which is used to open a lock. A typical key consist
of two parts: the 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. The blade is
usually designed to open one specific lock, although master keys are
designed to open sets of similar locks.
Keys
provide an inexpensive, though imperfect, method of authentication
for access to properties like buildings and vehicles. As such, keys
are an essential feature of modern living in the developed world,
and are common around the globe. It is common for people to carry
the set of keys they need for their daily activities around with
them, often linked by a keyring adorned by key fobs and known as a
keychain.
House keys
A
house key is the most common kind of key. There are two main forms.
The older form is for lever locks, where a pack of flat levers
(typically between two and five) are raised to different heights by
the key whereupon the slots or gates of the levers line up and
permit a bolt to move back and forth, opening or closing the lock.
The teeth or bittings of the key have flat tops rather than being
pointed. Lever lock keys tend to be bigger and less convenient for
carrying, although lever locks tend to be more secure. These are
still common in, for example, many European countries.
The
more recent form is that for a pin tumbler cylinder lock. When held
upright as if to open a door, a series of grooves on either side of
the key (the key's profile) limits the type of lock cylinder the key
can slide into. As the key slides into the lock, a series of pointed
teeth and notches allow pins to move up and down until those pins
are in line with the shear line of the cylinder, allowing that
cylinder to rotate freely inside the lock and the lock to open.
These predominate in, for example, the United States of America.
Car keys
A
car key or an automobile key is a key used to open or start an
automobile, often identified with the logo of the car company at the
head. Modern key designs are usually symmetrical, and some use
grooves on both sides, rather than a cut edge, to actuate the lock.
It has multiple uses for the automobile with which it was sold. A
car key can open the doors, as well as start the ignition, open the
glove compartment and also open the trunk (boot) of the car. Some
cars come with an additional key known as a valet key that starts
the ignition and opens the drivers side door but prevents the valet
from gaining access to valuables that are located in the trunk or
the glove box. Some valet keys, particularly those to
high-performance vehicles, go so far as to restrict the engine's
power output to prevent joyriding.[1] Recently, features such as
coded immobilizers have been implemented in newer vehicles. More
sophisticated systems make ignition dependent on electronic devices,
rather than the mechanical keyswitch. Ignition switches/locks are
combined with security locking of the steering column (in many
modern vehicles) or the gear lever (Saab Automobile). In the latter,
the switch is between the seats, preventing damage to the driver's
knee in the event of a collision.
Keyless
entry systems, which utilize a remote control in place of a car key,
are becoming a standard feature on many new cars. Some of them are
handsfree.
Switchblade
key from a 2005 Land Rover LR3.Some keys are high-tech in order to
prevent the theft of a car. Mercedes-Benz uses a key that, rather
than have a cut metal piece to start the car, uses an encoded
infrared beam that communicates with the car's computer. If the
codes match, the car can be started. These keys can be expensive to
replace, if lost, and can cost up to US$400. Some car manufacturers
like Land Rover and Volkswagen use a 'switchblade' key where the key
is spring-loaded out of the fob when a button is pressed. This
eliminates the need for a separate key fob but can often make the
key large and uncomfortable to keep in pockets for extended periods
of time. This type of key has also been known to be confiscated by
airport security officials[1].
Master key
A
master key is intended to open a set of several locks. Usually,
there is nothing special about the key itself, but rather the locks
into which it will fit. These locks also have keys which are
specific to each one (the change key) and cannot open any of the
others in the set. Locks which have master keys have a second set of
the mechanism used to open them which is identical to all of the
others in the set of locks. For example, master keyed pin tumbler
locks will have two shear points at each pin position, one for the
change key and one for the master key. A far more secure (and more
expensive) system has two cylinders in each lock, one for the change
key and one for the master key.
Larger
organizations, with more complex "grandmaster key"
systems, may have several masterkey systems where the top level
grandmaster key works in all of the locks in the system.
A
practical attack exists to create a working master key for an entire
system given only access to a single master-keyed lock and its
associated key. This is described in Cryptology and Physical
Security: Rights Amplification in Master-Keyed Mechanical Locks
Locksmiths
may also determine cuts for a replacement master key, when given
several different key examples from a given system.
Control key
A
control key is a key used in interchangeable core locking systems.
The control key enables the user to remove a core in the cylinder,
with a specific combination and replace it with a core with a
different combination. In small format interchangeable cores,
similar to those developed by Frank Best of the Best Lock
Corporation, the key operates a separate shear line, located above
the operating key shear line. In other format interchangeable cores,
the key may work like a master key along the operating shear line
and also contact a separate locking pin that holds the core in the
cylinder.
Double-sided key
A
double-sided key is very similar to a house or car key with the
exception that it has two sets of teeth, an upper level standard set
of teeth and a lower, less defined set of teeth beside it. This
makes the double-sided key's profile and its corresponding lock look
very similar to a standard key while making the attempt to pick the
lock more difficult.
Paracentric key
A
paracentric key is designed to open a paracentric lock. It is
distinguishable by the contorted shape of its blade, which protrudes
past the centre vertical line of the key barrel. Instead of the the
wards on the outer face of the lock simply protruding into the shape
of the key along the spine, the wards protrude into the shape of the
key along the entire width of the key, including along the length of
the teeth.[2] Patented by the Yale lock company in 1898, paracentric
cylinders are not exceptionally difficult to pick, but require some
skill and know-how on the part of the person attempting to pick the
lock.
Skeleton key
A
warded lock fits both its key and skeleton keys its size or smaller.
A
bronze skeleton keyA skeleton key (or passkey) is a very simple
design of key which usually has a cylindrical shaft (sometimes
called a shank) and a single, minimal flat, rectangular tooth or
bit. Skeleton keys are also usually distinguished by their bow, or
the part one would grasp when inserting the key, which can be either
very plain or extremely ornate. A skeleton key is designed to
circumvent the wards in warded locks. Warded locks and their keys
provide minimal security and only a slight deterrent as any key with
a shaft and tooth that has the same or smaller dimensions will open
the lock. However, warded keys were designed to only fit a matching
lock and the skeleton key would often fit many. Many other objects
which can fit into the lock may also be able to open it. Due to its
limited usefulness, this type of lock fell out of use after more
complicated types became easier to manufacture. In modern usage, the
term "skeleton key" is often misapplied to ordinary bit
keys and barrel keys, rather than the correct definition: a key,
usually with minimal features, which can open all or most of a type
of badly designed lock. Bit keys and barrel keys can be newly-minted
(and sold by restoration hardware companies) or antiques. They were
most popular in the late 1800s, although they continued to be used
well into the 20th century and can still be found today in use,
albeit in vintage homes and antique furniture. A bit key is
distinguished from a barrel key in that a bit key usually has a
solid shank, whereas a barrel shafted key can be made either by
drilling out the shank from the bit end or by folding metal into a
barrel shape when forging the key.
Tubular key
A
tubular keyA tubular key (sometimes referred to as a barrel key when
describing a vintage or antique model) is one that is designed to
open a tubular pin tumbler lock. It has a hollow, cylindrical shaft
which is usually much shorter and has a larger diameter than most
conventional keys. Antique or vintage-style barrel keys often
closely resemble the more traditional skeleton key but are a more
recent innovation in keymaking. In modern keys of this type, a
number of grooves of varying length are built into the outer surface
at the end of the shaft. These grooves are parallel to the shaft and
allow the pins in the lock to slide to the end of the groove. A
small tab on the outer surface of the shaft prevents the pins in the
lock from pushing the key out and works with the hollow center to
guide the key as it is turned.
The
modern version of this type of key is harder to duplicate as it is
less common and requires a different machine from regular keys.
These keys are most often seen in home alarm systems, in the United
States.
Zeiss Key
A
Zeiss key (also known as a Cruciform Key) is a cross between a house
key and a tubular key. It has three sets of teeth at 90 degrees to
each other with a flattened fourth side. Though this type of key is
easy to duplicate, the extra sets of teeth deter lockpicking
attempts.
Do Not Duplicate Key
A
keychain, a simple way to hold keysA Do Not Duplicate key (or DND
key, for short) is one which has been stamped do not duplicate by a
locksmith or manufacturer as a passive deterrent to prevent a retail
key cutting service from duplicating a key without authorization or
without contacting the locksmith or manufacturer who originally cut
the key. More importantly, this is a control system for whoever is
the owner of the key, such as a maintenance person or security
guard, to identify keys that should not be freely distributed or
used without authorization. Though it is intended to prevent
unauthorized key duplication, copying restricted keys remains a
common security problem. There is no direct legal implication in the
US for someone who copies a key that is stamped do not duplicate
(unless it is a government owned key), but there are patent
restrictions on some key designs (see "restricted keys").
The Associated Locksmiths of America calls DND keys "not
effective security", and "deceptive because it provides a
false sense of security."
United
States Code 18 USC Sec. 1704 deals with United States Post Office
keys, and 18 USC Sec. 1386 deals with United States Department of
Defense keys.
Restricted Key
A
restricted keyblank is a keyway and blank for which a manufacturer
has set up a restricted level of sales and distribution. Restricted
keys are often protected by patent, which prohibits other
manufacturers from making unauthorized productions of the key blank.
In many jurisdictions, customers must provide proof of ID before a
locksmith will duplicate a key using a restricted blank. These days,
many restricted keys have special in-laid features, such as magnets,
different types of metal, or even small computer chips to prevent
duplication.
Keycard
A
keycard, while not actually considered a key, is a plastic card
which stores a digital signature that is used with electronic access
control locks. It is normally a flat, rectangular piece of plastic
and may also serve as an ID card. There are several popular type of
keycards in use and include the mechanical holecard, bar code,
magnetic stripe, smart card (embedded with a read/write electronic
microchip), and RFID proximity cards. The keycard is used by
presenting it to a card reader; swiping or inserting of mag stripe
cards, or in the case of RFID cards, merely being brought into close
proximity to a sensor.
Bar
code technology is not a secure form of a key, as the bar code can
be copied in a photocopier and often read by the optical reader.
Magnetic
stripe keycards are becoming increasingly easy to copy, but have the
security advantage that one may change the stored key in a magnetic
swipe card in case the current key may be compromised. This
immediate change of the "key" information can be applied
to other media, but this media probably offers the least expensive
option, and the most convenient to users and managers of systems
that use this media. Example: If you own a car with this system, you
can change your keys anytime you want. You can buy new media
anywhere a gift card is sold. At least at this point in time, you
could buy a gift card for a penny, then use that as the media for
the keys to your car. If the system uses digital environmental data
samples to create the "key" string, every car can have a
set of keys that no one else has. If a card is stolen, or copied
without authorization, the card can be remade, and the car security
system can be synchronized with the new card, and no longer
activationally responsive to the copy of the old card. This approach
can empower the system controller (owner/individual or centralized
administration of a business).
Computerized
authentication systems, such as key cards, raise privacy concerns,
since they enable computer surveillance of each entry. Currently
RFID cards and key fobs are becoming more and more popular due to
its ease of use. Many modern households have installed digital locks
that make use of key cards, in combination with biometric
fingerprint and keypad PIN options.
The
first keycard was the mechanical holecard type patented by Tor Sørnes,
a concept he later developed into the magnetic stripe card key.
Other Info
A
key blank is a key that has not been cut to a specific bitting. The
blank has specific cross-sectional profile to match the keyway in a
corresponding lock cylinder. Key blanks can be stamped with a
manufacturer name, end-user logo or with a phrase, the most commonly
seen being 'Do not duplicate'. Blanks are typically stocked by
locksmiths for duplicating keys. The profile of the key bow, or the
large, flat end, often references an individual manufacturer.
Laws in the United States
Despite
common belief, keys stamped with "Do not duplicate" or
"It is unlawful to duplicate this key" are, with few
exceptions, perfectly legal to duplicate. Some key blank
manufacturers, such as Best Access Systems, strictly restrict the
sale of their own blanks. However, while the company may not sell
them directly, a consumer has every right to obtain blanks from a
third-party manufacturer. Some blanks are made only in small volumes
and are not widely available, but are not legally restricted. It is
legal to fabricate such a blank on a CNC milling machine.
Keyblanks
pre-stamped with powerless demands. These keys are not protected
under patent and anyone is free to make them.ALOA, an
internationally recognized association for locksmiths, also
considers such stamps an empty threat.[1]
Federal
law regulates the duplication/fabrication of keys for use with locks
owned by the US Postal Service and the US Military.
There
are a few states that impose some restriction at the state level.
California prohibits the duplication of keys for properties
owned/operated/leased/under the control of any state agency, not
limited to CA. Arizona has a similar prohibition, but the limitation
only applies to keys to State of Arizona facilities.
State
of California, penal code 469
“
Any person who knowingly makes, duplicates, causes to be duplicated,
or uses, or attempts to make, duplicate, cause to be duplicated, or
use, or has in his possession any key to a building or other area
owned, operated, or controlled by the State of California, any state
agency, board, or commission, a county, city, or any public school
or community college district without authorization from the person
in charge of such building or area or his designated representative
and with knowledge of the lack of such authorization is guilty of a
misdemeanor. ”
State
of Arizona
13-3715.
Unauthorized manufacture, duplication, use or possession of key to a
public building classification.
A.
A person who knowingly causes to be manufactured or duplicated or
who possesses or uses a key to any building or other area owned,
operated or controlled by this state or any agency, board,
commission, institution or political subdivision of this state
without authorization from the person, or his designated
representative, in charge of such building or area is guilty of a
class 3 misdemeanor.
B.
A person who manufactures or duplicates a key for himself or another
to any building or other area owned, operated or controlled by this
state or any agency, board, commission, institution or political
subdivision of this state, with knowledge that he or the person
requesting the manufacturing or duplication of such key does not
have authorization from the person or his designated representative
in charge of such building or area, is guilty of a class 3
misdemeanor.
State
of Kentucky
KRS
164.337. Duplication of university keys prohibited.
Elsewhere
Some
localities may have even more stringent regulations. Los Angeles
County has an ordinance prohibiting the duplication of any keys
stamped with "Do not duplicate".
There
is no implication of legal penalty, unless the key is restricted
under one of the criteria above.
If
one duplicates a key not legally protected under the above criteria,
but is protected by patents valid at the time of duplication, it is
a civil matter. Patented key blanks normally reference a patent
number and are protected by patent laws from unauthorized
duplication of the patented features. However, if the patent is
expired, one may duplicate the key.
There
are organizations and universities that claim their keys are
protected by law from duplication, but in the absence of a specific
law, such as those found in California and Arizona, the practice is
not necessarily illegal. However, if one signs a non-duplication
agreement when issued a key and subsequently makes a duplicate, one
maybe held civilly liable for a breach of contract. |
