The history of locks is vast and dates back to the times of the Old Testament of the Bible. Early locks were primitive, but could be highly effective, and they have changed over the years to become what we use today. There are several periods in the history of locks when they took on definite characteristics to match those of the architecture and culture of that time. Locks have grown to be more complex, and today can include very useful features such as keyless entry systems. Electronic locks are very useful, and today we can even lock our computers with passwords to protect information. Locks have played an important role in history and will continue to do so in the future.

In the beginning of time, man used hiding places to secure their valuables, and other inventive means to protect their goods. In India for example, valuables were sealed up and surrounded by crocodiles kept on low food rations so that anyone approaching would be quickly attacked and eaten. Other unusual ways of protecting valuables were complicated knots, so that the owner would know if someone had been tampering with their belongings. A lock in essence is any means to secure valuables and prevent theft or tampering; today, we consider locks to be mechanical devices that prevent unauthorized access.

One of the earliest references in the history of locks is the Old Testament. Judges 9:51 is about Abimelech leading a siege on the city of Thebes. The people of Thebes went into a high tower in the middle of town and barred the gate. The bar is one of the most simple and primitive forms of a lock, and it has been used since earliest civilizations. It is commonly found in primitive ruins of houses and dwellings and was commonly used later in history for securing homes at night from intruders. In America, settlers often used this as a means of protecting themselves from Native Americans or other settlers who might try to force entry into their homes.

One of the oldest mechanical types of lock came from ruins in Niveveh, and this type of lock has become known as an Egyptian door lock because it was widely used there. The lock was the primitive beginning of our modern pin-tumbler locks that are still commonly used today. The Egyptian door lock consisted of a bar with holes drilled in it. Wooden pegs inside the lock would fall into these holes when the lock was secured. A special key had pins that matched the wooden pegs in diameter, and spacing was used to lift the pins out of the way so the bar could be removed. Our modern pin-tumbler locks are similar in design, but have more pins and a more complex locking system.

At some time around the year 900, the history of locks changed to include the new all metal locks. They were simple with iron wards to prevent tampering. A warded lock has sets of round plates that match the shape of the end of the key. The most commonly recognized warded locks are those that use skeleton keys. The end of the key matches the wards inside the lock that allow only the correct key to turn and open the lock. Some of them were quite complex, and others were very simple.

As time progressed, locks took on the style of the periods they were created in, and there are many examples of highly decorative locks. During the Middle Ages and the Renaissance, locks and keys were highly decorated and often crafted to match their use. For example, locks for churches would be in the shape of a cross, extremely ornate and beautiful with lots of surface decoration. They were sturdy and often as secure as could be expected of the time.

Today, we have a broad range of locks and locking devices that take advantage of the most advanced designs and technology, many of which we can trace back to the early history of locks. The choices available are diverse, and some of them are extremely difficult to bypass. Locks used today range from simple door locks to very advanced locks that use electronics and magnets for powerful locking devices.

Today, people commonly have keyless entry systems for their cars, and these are available for houses. This is very convenient and secure when coming home with a load of groceries or other burdens. Another common modern lock uses very large magnets to hold the door shut. A button can be pushed to unlock them or a keycard held to a special sensor. These use an RFID tag, or Radio Frequency ID to determine whether the person seeking entry is allowed. The card has a small set of circuits that are activated when they come within range of the card reader, and an ID is determined. They are widely used in retail stores to prevent theft. The sensor is placed on the item and when it comes into range of the reader an alarm is sounded.

The vast history of locks shows how they have evolved into complex electronic locks and regular home use locks that are very similar in construction to those used hundreds of years ago. With time, locks will continue to become more complex and secure, but the old tried and true lock technology that has been around for so many years will also be used, because it works so well and is inexpensive. The future holds much new advancement in all areas, and locks surely will continue to change and evolve to meet the needs of future generations.