Master keying is a way to make multiple keys operate one lock. It creates a level of convenience for owners, managers, janitors, etc. to have access to multiple doors while controlling the access of individuals for certain doors. Master keying creates a security issue due to “ghost keys” being created. A ghost key is a key that is never cut but is still created in the lock. In most medium to large master key systems, for every door that has a master key and one operating key, there are at least 32 ghost keys that can open that door. This makes for a lot of convenience but really degrades the security of the door.
Maison (from the French meaning “house”) keying is generally used on the main or common door of an office suite or an apartment building. It allows all tenants to have separate keys to their space, but also have their key operate the main door. The doors to each space are “single keyed” and as secure as a lock can be, but the common door while being very convenient for everyone, is very unsecure. Many multiples of ghost keys exist for this door, sometimes hundreds, depending on the number of occupants requiring access and also how the system is designed.
In order to avoid additional charges due to multiple trips to your site it is best to gather some basic information required for every master key system. Begin with a floor plan of each building. Go to each door and determine the following:
** Human Resource file room, or patient file room, may need to be keyed different. It is not recommended, and possibly against HIPPA rules, to have doors to these files on a master key system. Please check with your regulating agency for their rules.
To maintain the integrity of your master key system we: