What is a Cipher Lock?

Mary Elizabeth
Mary Elizabeth

A lock refers to a number of types of device for securing a door. While there are combination locks, smart card locks, and keyed locks, the mechanism known as a cipher lock is opened with a programmable keypad and — according to definition — is not a true lock. There is also a specific type of cipher lock called a Cypher Lock®, which was developed by Continental Instruments, now a division of Napco Security Group.

A cipher lock is opened with a programmable keypad.
A cipher lock is opened with a programmable keypad.

The U.S. Army distinguishes the use of cipher locks and keyed locks, stating that the purpose of keyed locks is to maintain physical security, while the purpose of cipher locks is to control access, limiting either unannounced intrusions or unescorted entry to particular areas of a facility that are sensitive. Cipher locks are used to control access to areas such as airport control towers, computer rooms, corporate offices, embassies, areas within financial institutions, research and development laboratories, and storage areas holding weapons, controlled substances, etc.

A cipher lock may have four or five pushbuttons, depending on the manufacturer. Even with five pushbuttons, the code may be one to five digits. When the cipher lock unit is set up the code is programmed and shared with authorized personnel. It can be changed at any time.

Cipher locks are available in a variety of metallic colors and can be equipped with either a knob or a lever. The system may be mechanical, as is the case with the cipher locks made by Simplex or electronic, as is the Cypher Lock®. An electronic system allows for unlocking the door from a location within the room when a visitor who does not have the code arrives.

The Cypher Lock® in particular can be combined with a set time for opening the door as well as a battery standby system. Three types of alarm system are available. A burglar alarm interface is available to indicate when the door is breached. An error alarm can reveal someone who tries to guess the code. Finally, a hostage alarm can be triggered to indicate that entry was made under duress.

Mary Elizabeth
Mary Elizabeth

Mary Elizabeth is passionate about reading, writing, and research, and has a penchant for correcting misinformation on the Internet. In addition to contributing articles to EasyTechJunkie about art, literature, and music, Mary Elizabeth is a teacher, composer, and author. She has a B.A. from the University of Chicago’s writing program and an M.A. from the University of Vermont, and she has written books, study guides, and teacher materials on language and literature, as well as music composition content for Sibelius Software.

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Discussion Comments


Most people have never seen a cipher lock. They just call any locking device with buttons a cipher lock. Are all padlocks "master locks"? Kind of like how "Band-aids" is a brand name, but everyone calls all elastic bandages "band-aids".


Can the electrified cipher lock function with batteries only?


The part of the article that I thought was interesting was where the author talked about the electronic type of door equipped with a cyber lock. A person in the room could actually let someone in who didn't have a code. The door can be unlocked from any place in the room. I wonder how the people in the room could know for sure who was requesting to come in? It seems like it would be a secuty issue.


@anon156778 - I was wondering the same thing. I goggled cipher locks and came up with numerous sites that explained the steps you need to take to change a cipher door lock. There are about eight steps to follow.

First you need to release the passage feature of the lock. The turn key/knob needs to be in a vertical position. It's a fairly simple procedure.


When the combination is forgotten, how is the combination reset?

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