Master keying

Master Keying
– A master key operates a set of several locks.
– Master-keyed locks have a change key and a master key.
– Master keyed pin tumbler locks often have two shear points.
– Some locks have two cylinders, one for the change key and one for the master key.
– Master keyed lock systems generally reduce overall security.

Maison Key System
– A maison key system permits a lock to be opened with multiple unique keys.
– Maison key systems are often found in apartment buildings.
– Each individual lock in a maison key system can be operated by every key within the system.
– Some jurisdictions prohibit the use of maison key systems in certain complexes.
– High-security or electronic access control systems are used as alternatives in these locations.

Skeleton Key
– Skeleton keys are mentioned in the “See Also” section.

Fire Brigade Key
– Fire brigade keys are mentioned in the “See Also” section.

– ‘Types of Keys used in hotels for effective Key control.’ Retrieved 28 October 2021 from
– Blaze, Matt (March–April 2003). ‘Rights amplification in master-keyed mechanical locks.’ IEEE Security & Privacy, 99 (2), 24–32. doi:10.1109/MSECP.2003.1193208.Sources: