Security: The Long History of the Lock and Key

The modern-era definition states that a lock is a mechanical device or innovation that is used for fastening any physical entity. This lock is triggered and released with the use of an object called a key. Today, we have many different types of locks and keys that are accessed with code combinations, fingerprints, key cards, and others. But there is a long history behind how locks and keys came into existence in the first place.

Most 21st-century people are unaware of the long history of the locks and keys they take for granted today. The pre-modern history has a lot to say and convey to the people of the modern era about the origins of locks and keys.

Locks came into existence 6,000 years ago and were used in ancient times to secure palaces and private properties. People in ancient times were always interested in better locks and keys, and the mechanisms that they used. History has laid the foundation for the mechanism of locks and keys to grow and evolve even in the modern era.

Locks and keys: The earliest form of security was the so-called Egyptian lock. Note the hole where a human hand reaches in to open the lock. (Precision Locksmiths UK)

The First Lock and Key: The Egyptian Lock

The first lock design ever was discovered in the Nineveh ruins of ancient Iraq. Nineveh was an old and ancient Assyrian city that was located on the outskirts of the modern city of Mosul, on the eastern bank of the Tigris River. Nineveh was known as the largest city on planet Earth for many decades. The Nineveh lock, also known as the Egyptian lock, was made from a large block of wood. It is rumored that it was used for protecting the Khorsabad palace near Nineveh, as it was found in its ruins.

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This Egyptian lock was of the pin-tumbler type. This was the first and simplest form of lock, a wooden bar and bolt across a doorway. For opening or operating such locks, there was a hand-sized opening on the door that could be used to open the lock. Over time, this hand-sized hole became smaller and smaller. These holes were for the long prodders made of wood or metal that lifted up the bolt or bar, thereby engaging or disengaging the lock.

Later, the Egyptians improved this locking device by adding wooden pegs to it. These pegs used to fall into the holes within the bolt when the lock was engaged. Hence, it started the revolution of strengthening locks, as with these improvements, the locks couldn’t be disengaged without lifting the wooden pegs. Some pins were installed onto the long wooden prodders to disengage the wooden pegs and lift them out from their bolt holes to unlock the device.

These improved Egyptian locks of the pre-modern historical era were 2 feet (61 cm) long. The keys to these locks were about the size of a toothpick. Moreover, the invention of tumbler locks with functioning wooden pegs laid the foundation for modern locks.

The key for an ancient Roman lock. (ernstboese / Adobe Stock)

The Locks and Keys of Ancient Rome

The ancient Romans were the first to upgrade from wooden locks to metal ones between 870 and 900 BC. They developed metal locks and bronze keys that are familiar to us even today. They took over the Egyptian model and made certain improvements by adding wards, obstructions, and projections within the lock. These projections and obstructions were added to the lock in such a way that only a certain key could engage or disengage the lock. They were called “Warded Locks”!

The Romans went on to invent portable padlocks that had a U-shaped bolt. As per historical records, this type of lock was also independently invented by the Chinese. Some of the Roman-built locks were integrated with springs for holding the tumblers within the lock. Ultimately, Romans wanted to make the smallest locks possible, so that the keys could be worn as “finger keys.”

The idea of smaller locks was especially attractive to affluent Romans, who used to keep their valuables stored in locked boxes within their homes. And the locks were made smaller for such boxes. This allowed them to wear the lock keys on their fingers in the form of rings. This idea was proposed and implemented to create two important benefits. One is that the key was handy at all times, and it signaled that the wearer of the key was wealthy enough to have a secure box in their home. Secondly, the keys in hand provided a sense of security to the owners as it made the jewelry and money they had locked away at home “safe.”

A painting of a medieval locksmith in 1451 AD by an unknown artist. (Public domain)

Locks and Keys In The Medieval Age

In the medieval age, locks and keys became even better. In the Medieval Age lock making was already an established trade. Some of the improvements to locks in the Medieval Age included adding increasingly complex wards to the lock mechanism and the embedding of pivoted tumblers within the locking mechanism.

Medieval locks were known for their lavish design and embellishment. But soon problems arose. As aesthetics became increasingly valued security was “sort of” neglected.

The craftsmanship of medieval locks was impressive and even stunning, but they were not efficient in terms of offering security against theft. Skilled thieves were able to break these lock mechanisms with considerable ease. Moreover, the elaborated warding systems within these medieval locks were also failing, as it was easy for the thieves to “pick” them.

A medieval Gothic lock, from the 15th–16th centuries AD, made of iron, in the Metropolitan Museum of Art (New York City). (Metropolitan Museum of Art / CC0)

Gothic Locks

In the 17th or 18th century AD, Gothic locks came into existence. These locks were similar to those of the 14th century. Some of the earliest Gothic locks were found and likely made in the Belgian city of Lier.  Gothic locks were distinctive. They were designed and decorated with foliage that was mostly in a V-shape that surrounded the keyhole.

Gothic locks were also known as “drunk man’s locks” as a person, even when drunk, could easily find the keyhole to disengage the lock, even in total darkness.

Photograph of a small Chubb Detector lock fitted to a circa-1910 gun case. The inset shows the top-plate of the lock. (KillingForCulture / Public domain)

The Modern Era of Locks and Keys

The modern era came with perfect lock inclusions and exclusions and added strength, durability, and also appealing design features. The onset of the Industrial Revolution in the 18th century resulted in precision engineering and component standardization. Modern era locks and keys were manufactured with a much higher degree of sophistication and complexity.

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The modern age for the lock and key began in the year 1778 in England. Robert Barron was the first person to patent a tumbler lock embedded with a double-action mechanism. Barron’s lock was also called a “multiple tumbler” lock. It had an attractive design and high-end engineering that resulted in a much higher level of security. Along with that, this lock also embedded the concept of engaging all levers.

The new lock patented by Robert Barron had two tumblers that were the acting levers. These tumblers or levers need to be raised to a specified height to open the lock. These locks were not accessible without a key that had the correct notching. The notched key could raise each tumbler or lever within the lock. But Barron’s lock was still not entirely secure, even with two tumblers. A determined and skilled thief could still pick or break the lock.

In 1818, Jeremiah Chubb introduced a “convict defying detector” to Barron’s lock design. This detector was in the form of a special lever or spring that gets activated automatically if any of the existing levers or tumblers are raised too high. With this detector spring or lever engaged, the lock would jam, and the bolt could not be released anymore. Hence, it will also let the owner know that someone without the key had tried to open the lock. Chubb’s lock design was much more secure as a result.

But really reliable lock security was not achieved until the innovations introduced by Joseph Bramah, an English engineer. He crafted the first pick-proof lock in the year 1784 after Robert Barron’s lock and before Chubb’s new improvements. Bramah exhibited his lock in the front window of his shop with a sign offering a reward to anyone who could pick it.

A locksmith showing a Yale lock mechanism to client. (auremar / Adobe Stock)

Bramah’s pick-proof lock remained “unpickable” for 50 years. Then a skilled American mechanic picked Bramah’s lock but it took him 51 hours to open it. This pick-proof lock was only 4 inches (10 cm) long but still complex enough to foil most would be thieves.

However, Bramah soon discovered that he could not produce his locks fast enough to satisfy demand. The traditional method of making these locks was just too slow.

The pick-proof locks by Bramah consist of a notched diaphragm plate and radial slides loaded with springs. These springs were pushed down with the help of a notched key until the notches within it matched the diaphragm plate.

To produce these precision instruments faster machine tools were required. Therefore, Bramah partnered with Henry Maudslay, another English engineer, to develop the first machines for the mass production of locks.

In 1861, Linus Yale Jr, an American inventor, developed the Yale cylinder lock. This lock consisted of a pin-tumbler mechanism, which was used by the ancient Egyptians. Today, this is the type of lock that people most commonly rely on. It comes with a flat, small key that is grooved and has serrated edges. The key edges raise five pins within the cylinder, placed at optimal specified heights to allow the cylinder to turn.

These pins within the cylinder were then varied in length to result in countless other possible lock combinations. This meant that two notched keys would never be the same. Yale took advantage of existing mass-production methods and manufactured a entirely more secure and durable generation of locks.

Yale cylinder locks are very difficult to pick or open without the proper key. They became the locks that people used on their front doors, building entryways and in their cars.

Closeup of a woman's finger entering the password code on a smart digital touch screen keypad entry door lock for a hotel room. (myboys.me / Adobe Stock)

The Ongoing Evolution of Modern Locks

After Yale’s cylindrical locks became popular, they were further improved by modern engineers and technologies. Soon there were keyless combination locks, digital locks, fingerprint locks, and more.

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However, the era of mechanical locks continues. Modern mechanical locks combine the functionality of Bramah’s early designs, Yale’s cylinder lock, and the combination lock. Today, many locks have multiple features drawn from earlier historical inventions.

Top image: An old lock and key. Source: Dario Lo Presti / Adobe Stock

By Bipin Dimri