Tom has 17 years experience as a commercial locksmith and over 20 years in door hardware distribution.
Key Control Systems
You can buy locks that require special keys, called "restricted" keys, that take special documentation or identification to have made, and you can buy special key cabinets in which to store and track keys, but key control is not something you can buy. It is something you exert.
The key to key control is organization. A good key cabinet can help, but a key system must be managed by a person or persons to be effective. The key system manager must be prepared to chase down a key that has gone astray or change the system so that the errant key is eliminated. The manager must also be knowledgeable enough to know when these actions are necessary and how to help prevent breaches. I hope this article will be helpful in preparing a person to manage a key system.
Key System Structure
Think of a master-key system as an army of keys.
- Passkey: The lowest link on the chain of command is the passkey. Typically, this key opens one lock in the system.
- Submaster key: Submasters open more than one lock within a system but not all locks. One might assign submaster keys, for example, to floors in a high-rise commercial building.
- Master key: The Master opens all the locks within that system.
- Grandmaster key: Typically grandmasters are used where large numbers of locks are involved. For example, a commercial real estate management company might manage a dozen high-rise buildings, each with its own master key, and they might also have a grandmaster that opens all the locks in all the buildings.
The further up you go in the chain, the greater your vulnerability. For example, if you give a pass key to a repair person and that person steals something and disappears, as key system manager, you must have one lock changed. If you gave the repair person a submaster key, you would have to change all the locks that the submaster operates.
There are a finite number of key changes possible within any given key system, limited by the number of cuts, number of possible depths, permissable disparity of adjacent depths, and subtraction of unusable combinations. In addition, whenever a lock is keyed to more than one key, a number of theoretical keys, called incidental keys, could also open that lock if they were created. When these keys are created and used elsewhere in the system, it is said that those locks are cross keyed. Elimination of these incidental keys also limits the number of changes possible within a master key system.
One way lock manufacturers have worked to increase the number of possible changes is to create hierarchical key sections. The key section (or keyway) is the shape of the key that permits its insertion into a lock. Because a key of one section cannot be inserted into a cylinder of another section, changes can be effectively reused within a system, expanding the number of usable changes.
Standard keys raise tumblers inside a lock to a certain level that permits the cylinder to turn, unlocking the lock. Some cylinders incorporate what amounts to an extra set of tumblers that cause the key to perform two simultaneous mechanical processes instead of one. These high security locks have greater resistance to simple entry techniques such as picking and bumping, and sometimes drilling. Usually they also offer restricted keys - that is, keys that are difficult to get duplicated without proper documentation.
Two examples of restricted keys are Medeco and Schlage Primus.
The key system manager's job is to know where, who, why, and when, that is, where a key works, who it is that took the key, why they took the key, and when they took it and when they are supposed to bring it back. One of the most useful tools in handling this information is the key storage cabinet.
If keys will be handed out by an individual, the cabinet should be situated so that anyone who wants the key must ask the individual so that the individual can record the name, date, and time the key was taken. If access to keys will be supervised by an advanced technology key storage device its location is not as critical.
The key cabinet is a great place for key control and access control to collaborate. Personnel can use their proximity card, PIN code or other credential to gain access to keys. The access control system can time-stamp the event when they use their credential to gain access to the key cabinet.
Key Systems, Inc., a long time leader in key control field, offers a wide variety of sophisticated choices with their extensive line of secure storage systems. Below is a picture of their Security Asset Managers (SAMs) line of products. Notice the PIN pad access control with LED display. Visit their site to learn how a key cabinet can help keep track of keys, who is using them and when.
Key Tracking and Identification
If you are managing a key system for a system of 100 locks or less and demand for keys is not constantly high, a simple spiral notebook, divided into columns for name, key number, location, time out and time in should suffice. If you are managing hundreds of locks with high traffic in and out of the key cabinet, you will be better off using a spreadsheet program. If organization is not your strong suit or you find the number of entries in your system daunting, key system management software is available from several manufacturers. Ask your locksmith or security professional for advice on which program might be best for your needs.
There are traditional numbers used by locksmiths to identify keys within a system. You can use the traditional system or devise your own and give it to the locksmith to apply to your key system.
The most important factor concerning key tracking is that you do it. If you don't do it, you don't have key control; you have key OUT OF CONTROL.
The traditional key numbering system goes more or less like this with variations depending on who you talk to. The system designates the top key, "A". if "A" is a grand master, masters might be designated "AA", "AB", "AC", etc. Submasters under each master would go like this: "AAA", "AAB", etc. Pass keys would have numbers like this: "AAA1", "AAB2", etc. In this system, the key, "AAB3" would be key number 3 under submaster AAB under master AA under grand master A.
What is important about a key numbering system is that it helps the key system manager quickly identify any key within the system. However, any key numbering system can be defeated by users who duplicate keys without having the numbers from the original stamped on the duplicate. This is another reason to use locks that have restricted keyways that only allow key duplication by those authorized by the factory to do so. Some companies have keys that are even more secure.
The Medeco lock company, for example, offers patented keyways that are effectively controlled and keys that have on-board electronic credentials that make them more secure, much more difficult to duplicate and much easier to identify and track.
The final message I would like to leave you with about key control is that it is not a thing you buy but a force that you, as manager of your key system, exert. No technology will help those who lack vigilance and organization; but if you are vigilant and organized, there are many technologies available to help you.
May you always feel secure.
© 2008 Tom rubenoff
Keith B on April 27, 2015:
I just wrote a blog post about the same topic. Feel free to comment on it and continue this discussion.
Tom rubenoff (author) from United States on June 01, 2012:
Very true, Lee, thank you. A master key system is really the ultimate test of key control. It has its place - hotels, assisted living facilities - but if one loses control of the master key it is the same as losing control of all the keys.
Lee on June 01, 2012:
Just know that Masterkeying locks is a convenience item. Not a security item. (one way to put it is that "Masterkeying is the organized destruction of security.")
Masterkeying that is not done properly, that is - done according to a properly laid out system, with documentable charts, schedules, etc.. is even worse !! Utter Chaos !!
Pete johansson on October 07, 2010:
Really useful post there i work at a leisure centre and am currently having a renovation will be very helpful.
Tom rubenoff (author) from United States on September 10, 2010:
Thank you, Mr. Edwards!
Billy B. Edwards Jr., CML on September 09, 2010:
Good article. Another thing that will help is to have an established policy whether you have 25 locks or 2500. Your policy should cover issuing key and returns, deposits that may be required, established procedures for rekeying and even lists of authorizing people in larger organizations.
As far as I know Locksoft is the only company that has such policies already written as well as the tracking software you mention.