Group items tagged

Common entrance suite / Maison keying (CES)[edit] This system is widely used in apartments, office blocks and hotels. Each apartment (for example) has its own individual key which will not open the doors to any other apartments, but will open common entrance doors and communal service areas. It is often combined with a master-keyed system in which the key is kept by the landlord.

Master keyed (MK)

A master key operates a set of several locks. Usually, there is nothing special about the key itself, but rather the locks into which it will fit.

A practical attack exists to create a working master key for an entire system given only access to a single master-keyed lock, its associated change key, a supply of appropriate key blanks, and the ability to cut new keys. This is described in Cryptology and Physical Security: Rights Amplification in Master-Keyed Mechanical Locks.[36] However, for systems with many levels of master keys, it may be necessary to collect information from locks in different "subsystems" in order to deduce the master key. Locksmiths may also determine cuts for a replacement master key, when given several different key examples from a given system.

Control key

A control key is a special key used in removable core locking systems. The control key enables a user, who has very little skill, to remove from the core, with a specific combination, and replace it with a core that has a different combination.

Do not duplicate key

A "do not duplicate" key (or DND key, for short) is one that has been stamped "do not duplicate", "duplication prohibited

Restricted key

A restricted keyblank has a keyway for which a manufacturer has set up a restricted level of sales and distribution. Restricted keys are often protected by patent, which prohibits other manufacturers from making unauthorized productions of the key blank. In many cases, customers must provide proof of ID before a locksmith will cut additional keys using restricted blanks. Some companies, such as Medeco High Security Locks, have keyways that are restricted to having keys cut in the factory only. This is done to ensure the highest amount of security. These days, many restricted keys have special in-laid features, such as magnets, different types of metal, or even small computer chips to prevent duplication.