History of locks

Securing one’s property has long been a concern of people throughout the world. Beyond hiding the objects or constantly guarding them the most frequently used option is to secure them with a device. Early solutions included knots to either detect, like the Thief knot, or hamper, like the Gordian Knot. Historians are unsure where the first lock was invented, but evidence suggests that locks initially developed independently in the Egyptian, Greek, and Roman civilizations. Wooden locks and keys were in use as early as 4,000 years ago in Assyria . The first known lock with a key is a pin lock. The lock is strung on a rope hanging out of a hole in a door. A cylinder of wood with a hole drilled through its axis is the key, the length of the cylinder being the critical factor. The key is inserted into the hole and the bolt is pushed the correct distance. To lock the door the rope was pulled to extract the key cylinder, simultaneously pulling the bolt closed. This type of lock is still in use in certain parts of the world. Puerto Rico still uses this system. A disadvantage of this lock is that a vandal can push the rope into the hole — an ancient equivalent of putting glue into a lock.

In the early 1900s a wooden pin lock with a wood key was discovered in Egypt and is believed to have been used in 250 b.c.

Early improvements in pin locks included increasing the number of pins to increase security, and changing the orientation of the pins to allow the key to provide the unlocking force instead of a rope, thus establishing the principles of the modern pin tumbler lock.

Next was developed a warded lock that is still used in modern times when the security required is not high and cost is a significant factor. It is the first lock design to have a key recognizable to a modern western person. Lock puzzles were used to obscure the locking mechanism or even provide a non-functioning lock for the thief to waste time on.

Types of locks

A typical combination lock.Locks may be entirely mechanical, or electromechanical. They may be operated by turning some form of removable key, by keying or dialling in a combination which directly or via electromechanical means operates the lock, with some form of magnetic or other card reader, or by moving a part on a safety lock intended to prevent accidental operation rather than to prevent unauthorized access.

Tumbler locks, Pin-tumbler lockThe Pin tumbler lock is the most widespread lock in the western world.Pin-tumbler locks have been around in some form since 2000 BCE. The Egyptian form of this lock was large, heavy, and made of wood, with pins made of metal, usually bronze, but sometimes iron. This design in its modern form was first patented in 1805 in England. The patent holder was an American named A.O. Stansbury. In the middle of the 18th century, the American locksmiths Linus Yale Sr. and his son, Linus Yale Jr., refined the lock design into the form recognizable today. These early versions of the pin-tumbler lock were expensive to produce, and did not become widely available until mass production became feasible.

Wafer-tumbler lockThe first patent for the wafer lock was issued in the United States in 1868 to P.S. Felter. The wafer lock is relatively inexpensive to produce and is often used in automobiles and cabinetry. This type of lock is generally made of die-cast zinc alloy.

Lever locksLever locks were invented in Europe in the 17th century.This is a popular lock type for safes and North American prisons today, as they are generally built of strong materials. They are also used as door locks in some countries. This is the type of lock that replaced the medieval warded lock in the 19th century. Robert Barron of England patented the double-acting lever in 1778. Jeremiah Chubb would follow with his own detector lock in 1818.

Locksmithing

Locksmithing began as the science and art of making and defeating locks. A lock is a mechanism that secures buildings, rooms, cabinets, objects, or other storage facilities. A key is often used to open a lock. Means of opening a lock may include a security token or two-factor authentication for greater security, such as requiring both something you know (a combination) and something you have (a key or keycard).

The oldest known lock was approximately 4,000 years old and was of Egyptian make. It was found in the ruins of the Emperor Sargon II’s palace in Khorsabad. It used the same pin tumbler principle employed by many modern locks.

Historically, locksmiths actually made the entire lock, working for hours hand cutting screws and doing much file-work. Today, the rise of cheap mass production means that this is no longer true, and, though a few expert locksmiths are also engineers and capable of sophisticated repairs and renovation work, the vast majority of locks are repaired by swapping of parts or like-for-like replacement, or upgraded to modern mass-production items. Until more recently, safes and strongboxes were the exception to this, and to this day large vaults are custom designed and built at great cost, as the cost of this is lower than the very limited scope for mass production would allow, and the risk of a copy being obtained and defeated as practice is removed.

Although fitting of keys to replace lost keys to automobiles and homes and the changing of keys for homes and businesses to maintain security are still an important part of locksmithing, locksmiths today are primarily involved in the installation of higher quality lock-sets and the design, implementation and management of keying and key control systems. Most locksmiths also do electronic lock servicing, such as making keys for transponder-equipped vehicles and the implementation and application of access control systems protecting individuals and assets for many large institutions.

In terms of physical security, a locksmith’s work frequently involves making a determination of the level of risk to an individual or institution and then recommending and implementing appropriate combinations of equipment and policies to create “security layers” which exceed the reasonable gain to an intruder or attacker. The more different security layers are implemented, the more the requirement for additional skills and knowledge and tools to defeat them all. But because each layer comes at an expense to the customer, the application of appropriate levels without exceeding reasonable costs to the customer is often very important and requires a skilled and knowledgeable locksmith to determine.