Locks have changed over the centuries, but the struggle to optimize the balance between security, cost and convenience is a constant. From the days when the Maharajahs of India kept their treasure on islands surrounded by crocodile infested moats (access was only possible by killing or drugging the crocodiles) to the present age of electronics.
We know that wooden locks were in use four thousand years ago, the oldest found to date is from a palace in Nineveh (now Mosul, Iraq). Keys of this era were so large that a slave was required to carry one – not much more convenient than the crocs.
The Romans combined Egyptian, Greek, and Chinese improvements and made metal locks widely available. Because Roman togas had no pockets keys small enough to be incorporated into finger rings were developed.
Development of locks in the Middle Ages was mostly confined to cosmetics. Locksmithing was ruled by Guilds which often combined the worst features of cartels and unions preventing new technology from emerging, what inventiveness there was was directed to trickery, false keyholes and hiding the real lock to foil thieves.
At this time combination locks were known and used but could easily be defeated by “feel.”
In 1778 Robert Barron of England invented the lever tumbler lock, this provided real pick prevention for the first time and ushered in an age of invention.
In 1784, Joseph Bramah displayed in his London shop a lock with a sign offering 200 guineas (Â£210) to anyone who could pick it, it was not until 1851 that the prize was awarded, and then after 51 hours of effort.
Linus Yale jr., obviously a modest man, developed his “Infallible bank lock” in 1851, this was the standard for safes, but was soon made obsolete by the technique of pouring explosives into the keyhole. Precision combination locks replaced these, YaleÂs “Magic bank lock” came out in 1861.
1873, James Sargent, of Rochester, NY invented a time lock mechanism, to open the safe it was necessary to know the combination, and also the time window when opening the lock was possible.
Now is a period of rapid technological advance similar to the late 18th century, our revolution however, is in electronics rather than mechanisms.
Changes in Value
In the nineteenth century it was gold and diamonds that required the ultimate protection; todayÂs gold is data, todayÂs diamonds are civilian lives. Electronic firewalls have taken the place of fire-proof safes. Hard disks have replace bullion.
Information, such as medical records which, 25 years ago, were treated as worth little more than the paper they were written on, are now of enormous value and must be kept confidential. Identity thieves make their livings by stealing codes, passwords etc. to access bank accounts and credit. If on-line retailers cannot guarantee security they will lose their customers.
In the “West,” as life has become easier, the value we place on human life has increased, epitomized by our grief over losing 5 aircraft in a whole war; compared with just 60 years ago when the loss of 5 planes (40+ men) in a single 100 bomber raid would not have made the front page. With this increasing (perceived) value has come an increased tolerance of the extra cost and inconvenience in airports.
Many times just the appearance of a lock is enough to deter the casual thief. In other cases it is important that the door is actually locked. Occasionally it is important that the door is seen to be locked. To achieve this the lock can be designed to retain the key when unlocked, or the key can be used to free the handle which then springs out to an obviously “open” position.
99% of all locks are operated by conventional keys. So obviously they work very well and are cost effective in most applications. Key locks do have limitations as can be seen in the adjoining table 1.
Very high security keys are available which are very difficult to copy with replacements available only from the manufacturer. This is a significant cost in terms of record keeping and inconvenience as well as Dollars. The complexity of the key is no defense against theft.
All other keys are relatively easy to copy (even when stamped “Do Not Copy”).
The picture of the prison guard with a huge ring of keys may be anachronistic, certainly it highlights the inconvenience, but it has virtues, something that big and heavy is unlikely to be lost and its theft is immediately obvious. In most collocation centers and data centers a master key system is used to improve convenience by allowing one key to open all doors in the system with subordinate keys authorized for just one, or one set of doors. This eliminates the need for say a maintenance man to carry large number of keys. As always there is a trade-off: the master is very valuable.
A recent development is a handle operated by a combination with a key override; this operates like a mastered system, but locks can be fairly easily “re-set” in minutes, as say, tenants in a collocation center, or employees come and go.
It is not normally necessary to use a large number of different key patterns if any surveillance is used; someone trying 25 locks before one opens will not succeed.
Any system that requires keys has problems when a key goes missing, the first difficulty is for the responsible person to become aware of the loss. A decision must then be made as to the likelihood of the key falling into nefarious hands and from that the decision to re-key some, or all, locks is dictated. The expense and time wasted doing this, particularly if it is a master key that goes astray, suggests that it will not always be done. The property at risk if a key is compromised often does not belong to the holder of a master key, this presents a conflict of interests and is a good argument for lessees to demand a system that can be “re-keyed” easily and inexpensively.
A worse problem is when a key is copied, then only the person (perhaps an employee about to be terminated) who does the copying may know of this security breach. Again if “re-keying” is easy it can be done every time an employee leaves.
As the need for master systems has increased and the cost of electronic systems has declined more and more companies and other organizations are considering the “electronic alternative.”
Electronic Handles on Server Cabinets
With the increasing value of information much security attention has focused on computer security, both from electronic and physical entry. An electronic server cabinet security system such as EMKAÂs modular system can be configured in several different ways in order to combine security and convenience in the most appropriate combination.
A typical Bank Data Center or Collocation Center will have, perhaps, 250 server cabinets each with one, two or three doors front and rear. The enclosures are set in banks in a secure room. The room is typically accessed by an ID badge / proximity card. Several of the servers will be leased out to various tenants, they and their maintenance people need access from time to time. The management of the building also need access and the ability to lock out the lessee.