Have you ever wondered why it is that a single master key can open any of the locks in your entire apartment complex, while the one you have will only open your apartment door, and possibly the main entrance door to the building? While this specific scenario highlights a master key setup in an apartment complex, the same situation could be true with any number of other commercial and residential lock-and-key configurations.

The answer to the ‘one key, many locks’ question lies in a very clever arrangement of the components which comprise a lock and key system – but the same principle which allows that kind of master key access is also what makes this model vulnerable to a security breach if engineered by a skillful and knowledgeable criminal. Here’s why all that is true.

How Master Locks Work

Most locks are constructed using design concepts that are fairly uniform in the industry, the most common of which is the cylinder lock. With this kind of design, the key turns a cylinder which is attached to a cam, which then also gets turned. When the cylinder is turned in one direction, the cam or plug, causes the door to open by pulling in on the bolt. When the cylinder is turned in the opposite direction, the bolt is released by the cam and is snapped into place to prevent the door from opening.

Another common type of lock is the pin and tumbler design, which features a series of small pins, each having different lengths. These pins are separated into pairs, with each pair situated in a shaft that goes through the central cylinder cam, and on into the housing. The pairs of pins are kept in position by springs situated at the top of the shafts.

Before key insertion, the bottom end of each pair rests totally inside the plug, and the topside pin stays halfway inside the plug and halfway within the housing. The position of the upper pin is what prevents the plug from being turned because the plug is bound to the housing by the pins.

The fundamental principle which makes any master key system functional is that there are extra pins in the cylinder of the lock, and these allow for several differently shaped keys to achieving a compatible alignment with all sets of pins that they extend into.

Do You Need a Master Key System?

If you need a master key system to be installed at your home or place of business, the first call you should make is to a highly reputable commercial locksmith or residential locksmith in your area.

As mentioned earlier, some master key systems are more easily breached than others, because clever criminals can reverse engineer the system of pins in the cylinder to create their own master key. An expert locksmith can discourage this kind of criminal breach of security with a professionally designed master key system.

A Master key is one which is capable of over-riding all other locks configured in a master key system, and opening them up to gain access. No other key in that same system would have such a capability, having only the ability to open the single lock associated with that key. There are some obvious advantages to a landlord or property manager is having a master key system installed for a given building since it would allow access to all individual apartments within the building, and provide emergency access when needed. But installing a master key system also calls for some responsible control measures on the part of the holder, just because of the power it wields.

Points to remember about master keys

The worst-case scenario with a master key system would probably be to lose the master key itself or to have it found or stolen by someone with malicious intent. Someone holding that kind of power could access any apartment in a building, and be free to cause damage, remove objects at will, or even to bodily threaten occupants of the apartment – all while leaving no visible traces of entry. This means that only the most trusted individuals should be given access to a master key and that the location of a master key should only be known by someone who has the complete confidence of the landlord or property manager.

All other locks in a master key system can be completely changed out without affecting the access of the master key, and this allows a property manager to change locks after a tenant leaves without having to disrupt the master key system itself. That is just the kind of flexibility needed for large apartment complexes, where tenants routinely come and go. Security can be maintained in the master key system, without having to undergo the constant expense of changing the master key system itself.

On the negative side, an improperly designed or constructed master key can lead to the possibility of a knowledgeable criminal subverting the master key and gaining access to an entire building. This is because of the inherent nature of master key systems, in that the locks themselves are much easier to pick than individual locks, and a professional thief is often aware of this fact.

Conclusion

While the convenience aspect of master key systems is unquestioned, from the standpoint of security, high-security locks may be better options than multi-lock systems, especially in situations where entry to buildings could potentially be an issue. To install the right kind of security system for your apartment building which incorporates both convenience and security, you should contact your commercial locksmith and discuss your needs with an expert.