The Romans innovated further and substituted wood materials for brass keys and iron locks, making locks more resistant, and invented wards, a groundbreaking technological advancement, as it required the corresponding key to open a lock.

Warded locks remained the standard for several hundred years. So, nothing to mention, only that the Germans were manufacturing excellent locks that were better fitted and finished. Business as usual.

At the end of the 18th century, two English locksmiths and inventors, Robert Barron and Joseph Bramah, created new locking mechanisms.

While Barron patented a double-acting tumbler lock, Joseph Bramah created a new, highly secure lock mechanism that used a cylindrical key, a lock that remained unpickable for over 67 years.

In the middle of the 19th century, Linus Yale Sr. patented a pin tumbler lock that used a key with ridges of various heights to align a set of key pins correctly to allow for the lock’s barrel to turn. This mechanism was improved by his son, Linus Yale Jr., who patented a lock version with pins of varying lengths and the known small flat key.

The name “Yale” has become a common noun in certain countries, replacing the word “lock” itself, as Yale locks are still broadly used today all across the world.

Push Button locks – nice try, but…

Attempts to solve the key problems began with the invention of mechanical “push button locks”. These locks (still used today) require a predetermined combination of numbers/buttons that cause the lock to open once entered.

However, while these new locking mechanisms have freed people from managing the keys, they require users to remember the combination, keep the combination confidential, and change the combination regularly for security reasons. Too many …” combinations”.

First step – Punch cards

In the 1970s, a Norwegian inventor, Tor Sornes, conceived a system that would punch a series of 32 holes into a plastic card. These hole or punch cards required a cardholder to slide a unique card with holes into a slot “card reader”, which released the locking mechanism.  However, this technology had no long life because of its coding limitations, the labor involved in production, and its fragility.

Second step – Barcode cards

“Bar code cards” were the next innovation in key card technology. In this type of system, an individual bar code is printed on a card that corresponds with a particular lock. When the bar code is held under an electronic scanner, it unlocks the door. Simple and cheap.

While still used today, this technology cannot offer any security, as most of the barcodes could be easily replicated and the electronic reader could be easily fooled.

Childhood – Magstripe cards

By the 1980s, these card technologies had been replaced by a new one: the “magstripe card”.

This card, of credit card size, has a thin magnetic strip on the back. When it is swiped through a card reader, the electronic code recorded on the magnetic strip is read, and, if valid, the corresponding lock is opened.

Invented in the 1960s, mag-stripe cards were initially used for data storage purposes as debit or credit cards. Yet, being easier to encode and relatively cheap to produce, they were rapidly adopted by the growing security industry as unique “keys”.

The great benefits came with two serious vulnerabilities: easy to duplicate by informed hackers (the data was unencrypted) and eventually demagnetizing. Also, being a swipe technology, damaged cards and physical wear on readers became costly and time-consuming for administrators.

Adolescence – 1980s Wiegand cards and protocol – a technology that has mastered the game;

In the 1970s, an American physicist born in Germany, John Richard Wiegand, discovered the unique electromagnetic property of a specially designed wire. It was called the Wiegand Effect and based on this, a new card technology appeared.

The new access cards had built-in thin special wires, arranged in two rows corresponding to 0’s and 1’s.  When these cards are swiped through a slotted “Wiegand” card reader containing a magnet, a data stream is produced, which is then transmitted over two wires to a door controller.

The new cards were extremely secure, virtually impossible to duplicate, and very durable. Unfortunately, their manufacturing was so specialized, and a maximum of 37 Wiegand wire filaments could be placed in a standard card size before misreads would affect reliability.

The impact of Wiegand innovations has been so important for the security industry, as most of the access control systems used in the last 40 years were designed around Wiegand data formats. Proximity cards and contactless chip cards have all been encoded using this original Wiegand data structure. Wiegand wire technology has become a “de facto” standard for access control systems worldwide.

The maturity – RFID era – 1990s.

“Prox” cards

In the 1990s, the emergence of contactless technologies (Radio Frequency Identification–RFID) was a game-changer in the access control industry, lowering maintenance costs, increasing user convenience, and solving issues with magstripe and Wiegand cards.

The predominant technology during this stage is known as “Prox”, or “low-frequency proximity” (still used today in many legacy security systems).

A “Prox” card has a “unique” identification code (ID number) programmed on a chip (the “key”) embedded in a plastic card, about the size of a credit card.

The data is sent to a card reader via electromagnetic waves of low frequency of 125 kHz, when the card is detected in proximity to the reader (usually a few centimeters) and runs through the controller system.

Database access control became faster, more reliable, and more convenient.

However, technology has some important limitations: the data from the card is unencrypted and can be read in the clear, making the cards easy to clone or forge. Moreover, the Prox cards cannot be encoded with multiple IDs or other attributes.

Late 1990s-2010s – A more complex device – the Smart Card

Smart Card technology has been adopted by the security industry only at the turn of the century as an improved solution to “Prox” cards, despite it being conceptualised in the mid-1970s.

Physically similar to Prox cards, Smart Cards use a higher frequency (13.56 MHz) to communicate with the card readers, offer higher security, add multi-application functionality, and address the two main limitations of Prox cards:

• Mutual authentication – both the credential and reader contain a set of cryptographic keys (like a password). When the credential is presented to the reader, the two compare “keys”. If the keys match, the credential shares the binary data with the reader, and the reader accepts it as genuine. However, if the keys do not match, there will be no transaction, and the credential will keep the data private.
• A Smart Card could store more information than just an ID number, such as an electronic purse or a user biometric template.

In the last few years, smartcard technology has significantly evolved, and newer smart card generations (Mifare DESFire EV3, Seos) have come with even better security and more application capabilities.

The biometric solution

In short, with a biometric security device, the user doesn’t need to carry any physical key (key/card) as the person becomes “the key” itself. An electronic biometric device scans one of the several physical traits that differentiate one human being from another and runs it against the existing database.

The idea of biometric identification is quite old (from the Babylonian era), but it was not until the 1980s that the first “hand geometry” scanner began to be used in security systems, and in the 1990s, John Gustav Daugman, a British-American professor, made it possible for iris recognition technology to be applied commercially.

With advances in fingerprint scanning, voice, facial recognition, and especially AI, it’s entirely likely that new biometric technologies will play a major role in the security industry for decades to come.

However, given their current security vulnerabilities, GDPR concerns, and still prohibitive prices, for now, biometric technologies are most often used as an additional security layer of an RFID, especially for high-security areas.