Key Control and High Security Lock Mechanisms

Jan. 1, 2006
High security is a broad term, while key control is a level of security.

High security is a broad term. In our daily interaction with customers, we work with various types of security on various levels. Key control is a level of security.

Keys are designed to protect people and property. Keys get the authorized people in and keep others out. When people lose their keys, they panic! To play it safe, they get extra keys made. When we want someone else to get into a protected area, we give him or her one of the extra keys. This article will examine how the different levels of key control interact with the various levels of security.

Duplicate keys can be a benefit or a detriment to security. The problem comes when someone gets an unauthorized copy of the keys. If your customer ‘loans’ someone his or her keys or leaves them with a service person, how do they know they haven’t had unauthorized extra copies made?

By making copies without the owner’s knowledge, anyone can gain access to a home, business or vehicle at any time. This can result in burglary, theft, damage or personal injury. The solution is key control.


Key control is an important part of the overall security of a customer. Various levels of key control are available. High security locks are also a great way to increase the level of your customer’s security. A lock and key system can offer high security only, key control only or both. The issuance and duplication of keys must be considered when security is lacking, not just the pick and drill resistance of high security.


The primary function of the UL437 standard is to certify that a cylinder is both pick resistant and drill resistant. UL437 Listed cylinders have a series of hardened steel drill pins or discs added to pick resistant cylinders. Pick resistance is provided by a second or third level of protection provided by sidebars, check pins, finger pins, rotating tumblers, etc.


Key control may be accomplished on various levels. Different manufacturers offer a number of options. Duplication authorization can range from completely in the local locksmith’s control to completely in the customer’s control. Most locksmiths offer their customers a range of choices from different manufacturers.

The level of restriction may be controlled in a number of fashions. In the open level, any locksmith customer of a distributor is able to purchase lock cylinders, products and key blanks. This product is not available to the general public. Keys cannot be cut at big box stores and hardware stores.

In a slightly higher level, a contract signed by the locksmith assures the distributor that he will only copy keys generated by his company for his customers. Other locksmiths may also sell the same product, but they also agree to only generate or copy keys that they have initiated.

Some product is exclusive to the distributor. If a locksmith purchases a keyway from Distributor A, he must return there for that product. Distributor B has similar product but in a varying key section or side milling.

Other levels of restriction require a signature to match one on file. These cards are updated with key issue numbers, dates, and authorization information as each new key is issued.

Higher levels of key control allow the customer to use any locksmith to supply the product by issuing them a letter of authorization to purchase that product from the manufacturer. Other keys are available only from the manufacturer; duplication is prohibited by any other source.


Many keys are marked “Do Not Duplicate” in an effort to keep them from being copied without permission of the owner. This is the lowest level of key control.

For many years, this was the best way to address the issue. Most professional locksmiths would honor the intention. Today, keys are duplicated at the big box stores, auto supply stores, hardware stores and coffee shops as well as locksmith and security centers. Most places ignore the stamp. Even keys marked “Unlawful to Copy” aren’t safe.

When common, everyday keys are stamped “Do Not Duplicate,” some lock shops won’t cut them without a letter of authorization. As mentioned above, most places ignore the stamp. You need to follow the rules of duplication that you are comfortable with or your lock shop has agreed on.


Locksmiths have some security solutions by using restricted key sections. Available only at professional locksmith security centers, these keys have unique features that eliminate the possibility of getting keys copied at another non-locksmith location.

Cylinders or plugs are available to the locksmith that will retrofit into most popular Grade 1 and Grade 2 lock products. Restricted keys may be controlled at the locksmith dealer or at the locksmith distributor level.

Some restricted keys operate like any pin tumbler lock. The key section is unusual, but the mechanical operation is normal. Other restricted key sections also incorporate some high security features such as sidebars and anti-drill blocks.


The highest level of security can be obtained by upgrading to a patented key control system. Used in a variety of commercial and some high-end residential settings, this type of high-security lock and key can be designed to operate one door or all doors in a commercial master key system.

Duplication of keys may be controlled by an authorized signature or presentation of a plastic authorization card.

Accurate records are essential to maintain issuance, recovery and current status of all keys and their holders in any key control situation. Following are some specific details on some of the key control and high security products available.


Abloy’s extensive range of high security locking systems is based on their unique rotating disk locking mechanism, which provides increased master-keying possibilities and superior resistance to corrosion, manipulation and attack. The rotating disc operating principle is radically different from traditional pin tumbler and spring operated locks. These unique high security locking products have been designed to withstand most harsh environments, making them versatile and easily adaptable in the market.

The absence of pins and springs improves the durability, corrosion resistance and pick resistance of the lock, and makes it reliable, durable and cost effective high security. The Abloy rotating-disk cylinder system provides up to 1.97 billion possible key combinations, which ensures the flexibility and expansion capabilities needed to satisfy the demands of even the most complicated master-key systems.

Abloy EXEC, with patent valid until 2014, is the latest development. The EXEC product takes over from HIGH PROFILE. Additional keys are strictly controlled through the Abloy network of authorized service centers or by the factory.


For Interchangeable Core applications, Arrow ChoICe™ Base is the standard level of product. Available in Arrow and competitive interchangeable core keyways, Base is capable of all levels of keying for new or existing key systems. With an option to have drill resistant pins in the front, plug and shell, ChoICe™ Base offers convenience as well as a higher level of security. The ChoICe™ Base Core is 6 pin and drill resistant. ChoICe™ Base Core is also available 7 pin.

Choice HS and HSD is the highest degree of key control and security. The design process allows for a side bar locking mechanism to be incorporated. When hardened pins are added, the core meets and exceeds the requirements of UL437 for pick and drill resistance.


The ASSA Twin V-10 offers virtually unlimited keyways to the end-user on a geographically exclusive basis. New patents assure each user of protection against unauthorized duplication. The cylinder housing and inner plug are manufactured from solid brass. Pins are stainless steel and nickel silver. Precision machining insures smooth, positive operation and extended cylinder life.

Two independent shear lines help assure optimum pick resistance. “False” grooves in the side pins catch the sidebar when improperly positioned. When rotational force is applied, counter-milling in the plug catches the spool drivers.

Keys are manufactured from nickel silver. The rounded back allows smooth operation and minimizes wear. The use of the oversize key bow simplifies key identification and can be used by physically challenged people. The keys are guaranteed for life against breakage under normal operating conditions.


The Corbin Russwin Pyramid is a patented, high security lock system incorporating unique pin tumbler specifications and the secondary “Pyramid” locking mechanism. The “Pyramid” locking mechanism is operated by a spring loaded, control pin located on the bottom of the key blade. The Pyramid has patent protection against unauthorized key duplication through June 15, 2018. The high security Pyramid lock system has the UL437 Listing for resistance to drilling and surreptitious entry.

The Pyramid seven-pin tumbler locking system uses hardened stainless steel pins, having pick-resistant grooves. The seven-pin lock mechanism provides a four-fold increase of change key possibilities over a standard six-pin tumbler system. The Pyramid incorporates a secondary locking pin mechanism in the cylinder that engages a blocking plate on the plug and prevents the plug from rotating. An integrated spring loaded control pin is built into every Pyramid key.

The Pyramid high security locks are available in a number of proprietary Corbin Russwin keyways. Corbin Russwin determines pyramid keyway assignments. Keyway decisions are based on system requirements and geographic location. To maintain a high level of security, the Pyramid key sections cannot be integrated into existing Corbin Russwin systems. Keys can be duplicated or originated using standard key cutting equipment.


Medeco has long been a recognized name in key control and high security. Medeco offers various levels of key control in its product lineup.

Medeco3 is the brand’s latest technology. These cylinders have earned a UL437 Listing, the ANSI/BHMA A156.30 Level A certification, and are classified as high security because of their high level of resistance to physical attack and protection against unauthorized key duplication.

The Medeco3 locking technology employs pick-resistant pin tumblers that must elevate and rotate to the proper position and interact with a slider mechanism and sidebar for the lock cylinder to operate when the correct key is inserted.

The slider and sidebar are two components that provide additional locking of internal parts not found in traditional cylinders. The Medeco3 product line was introduced in 2003 with patent protection until 2021. Because of its high level of key control and physical strength, Medeco3 products are recommended for new installations or when retrofitting standard cylinder systems.

Medeco KeyMark offers a complete line of small format interchangeable core cylinders. These unique products utilize an offset blade design and various levels of key control. The patented Security Leg® keyway distinguishes KeyMark from ordinary interchangeable core lock cylinders and keys. KeyMark rim and mortise cylinders both retrofit locksets of major manufacturers and provide affordable replacement cylinders with genuine patented key control. This exclusive patent provides higher security by protecting against unauthorized copies of the keys. KeyMark rim and mortise cylinders both retrofit locksets of major manufacturers.


The Mul-T-Lock high security lock concept is a “pin-within-a-pin” pin tumbler lock mechanism. There are plug (bottom) pins and combined drivers that are similar in operation to the conventional pin tumbler lock mechanism. Mul-T-Lock combined drivers are comprised of external and internal pins. The spring-loaded internal pins of the combined drivers operate the internal plug pins. The external plug pins are operated by external component of the combined drivers. Both the internal and the external pins shear lines must be achieved simultaneously in order to rotate the plug.

To provide increased security, Mul-T-Lock offers the Interactive Restrictive Key Cutting System; a special “interactive” pin is embedded into each side of the convenience key blade. The “interactive” pin restricts the operation of these lock cylinders such that they can only be operated using an “interactive” pin equipped key.

Mul-T-Lock keys are handed with the grooves and cuts on one side of the blade. Each key contains a maximum of five double dimple cuts on each side of the blade. The keys enter the lock’s keyway horizontally, contacting the pins on the flat of the blade. The number of cuts varies depending upon the type of lock cylinders within a specific system. These high security lock cylinders are available as mortise, rim, key-in-knob/lever, and profile. The key-in-knob/lever cylinders are available with fixed or lazy cam tail pieces. They are available in three cylinder diameters to retro-fit into the different North American lock manufacturers lock hardware.

Cutting Mul-T-Lock keys requires the use of a special key machine to produce the double dimple cuts. This key cutting machine originates keys using two spindle mounted cutters.


Global Peaks provides enhanced security by employing three locking technologies. Pin tumblers are operated by the cut of the key. Peaks technology is operated by ‘peaks’ on the top and bottom of the key. Disc technology is operated by ‘wards’ built into the cylinder. Cylinders may be masterkeyed just like any standard cylinder.

Essentially this design creates three shear lines, making it more than three times more difficult to pick than cylinders with one shear line.

The new patented design gives locksmiths complete control of key duplication because authorization is required to order cut keys and to obtain key blanks and cylinders. Patents for Kaba Peaks Global will not expire until 2024.

Peaks Global locks are available to fit virtually every mortise, rim or key-in-knob application and retrofits virtually all Grade 1 and Grade 2 hardware. Peaks Global is not UL437 listed but rather conforms to the BHMA / ANSI 156.30M standard for contractual patented key control, master key ability, number of theoretical changes, cycle testing and various other destructive test requirements.


Extra security, exclusive end-user patterns, and patented key control are the main benefits of the Sargent Signature Series. The patented key design provides additional control against unauthorized key duplication, while the cylinder’s unique design resists attempts at physical manipulation. The Signature feature is offered in the majority of Sargent keyways to provide a solution to upgrading the level of control in an existing master key system. Signature cylinders retrofit into almost any Sargent lockset, as well as most commercially available brands of mortise locks and exit devices and are field serviceable.

Sargent Keso provides a factory controlled level of key control with a unique six-sided key design. The dimpled style Keso keys requires sophisticated key-cutting equipment. The unusual cylinder has three banks of pins that are extremely pick resistant. In addition, these three banks of pins enable multiple levels of master keying with no loss of security.

The Sargent XC (Extra Control) rounds out the family of cylinder products. The XC is a patented product available in many existing Sargent keyways allowing an easy, cost-effective backward compatible upgrade solution for existing key systems. Keys and cylinders are patented with keys available only through authorized Sargent distributors.

The XC Series incorporates a side pin mechanism working in conjunction with a specially milled key. The XC series is available in most SARGENT products, including Bored, Mortise, Auxiliary Locks, Exit Devices and Access Control products. Cylinder types include standard and Small Format Interchangeable Core.

The Sargent XC can’t be copied and supplied by others and can be cut to operate non-XC cylinders in an existing or new system. The keys can be field cut on standard key duplicating machines.


Prior to the introduction of Everest Primus, Schlage offered a high security cylinder compatible with their Classic obverse (C/CE/E/EF/F) keyways. This single offering was simply referred to as Primus. Since the introduction of Everest Primus, Schlage began referring to this original product as Classic Primus to help differentiate the two products.

The new product, Everest Primus, incorporates a new set of patented keyways with the proven Primus technology. The terms Classic and Everest describe the family of keyways that the product uses and the term Primus refers to the side bitting, finger pin and sidebar mechanisms.

While there are many similarities between Classic Primus and Everest Primus, there are some differences as well. Both products provide a high level of pick resistance and a means to help control unauthorized key duplication.

Since Classic Primus can be keyed in to existing Classic key systems, Classic Primus is still commonly used for key system upgrades. Everest Primus is protected by a total of four utility patents vs. two for Classic Primus. These patents allow Schlage to control the distribution of keys and provide a dealer or end user with geographic exclusivity on Primus keys.

Another difference between Everest Primus and Classic Primus is that Everest Primus uses a larger key bow that provides you with additional space to stamp information and makes the keys easier to handle.


Scorpion offers a simple, cost-effective answer to the key control problem. The Scorpion CX-5 line of products utilizes a security ridge milled into the side of the key blank at the factory. In addition to the standard cuts on the top of the key blade, this ridge provides an additional 200 extra keyways to provide pick resistance and duplication control. Keys can be code cut or duplicated on any standard key machine.

The shear line and sidebar anti-drill pins provide drill resistance while the combination of industrial-strength brass nickel and steel components offers a high degree of wear in the commercial application. Signature cards, kept on file by the locksmith, control authorized key duplication.

The combination mortise/rim cylinder comes with tailpieces, cams and screws to use it in either application. Deadbolts are available in all three grades and knob/lever cylinders come with multiple tailpieces to fit most common Grade 1 and Grade 2 hardware.


The patent protected Yale Security Cylinders make use of two independent locking mechanisms to provide high security protection, with a six- or seven-pin tumbler mechanism with spool drivers, and a five tumbler rotating disc/sidebar. The six or seven pint tumblers block the top of the keyway, while the five spring loaded, rotating discs block the bottom of the keyway. The operating key has a side bitting as well as the bitting to accommodate the pin tumblers. Once pin tumblers and the rotating discs align clearing the shearline, the cylinder plug can be rotated.

The Yale Security Cylinders use the “GST” and “VYZ” families of surety keyways in these cylinders. In addition to the key restrictions, the security cylinders are available for those applications that require UL 437 pick and drill resistance. These lock cylinders have a hardened stainless steel cylinder head and rotating plug face to the mechanical security

The Yale Security Cylinders are available in three Security Levels. The base level, level 1 is the Registered Distributor. This level uses the GST family of keys that come from the factory cut for the rotating disc tumblers. The pin tumbler bitting is cut by the locksmith enabling rekeying of the lock cylinders. Additional keys are available. Level 2 is the Registered to End User. This level uses the “GST” family of surety keyways. Lock cylinders are only available from Yale. The cylinders are factory assembled and keys are available from Yale. To obtain keys, an authorized signature is required from the building owner. Level 3 Registered to End User (Restricted Keyways) is the highest level of security. Level three lock cylinders use the “VYZ” family of restricted keyways. These cylinders are sold by locksmith wholesalers for specific jobs. Cylinders are factory assembled and keys are factory cut. Additional cut keys are only available from Yale and require an authorized signature from the building owner.


Key control is an essential part of the overall security package you provide to your customer. The needs of residential, light commercial, and heavy duty commercial customers vary by application, situation and budget.

Key control on exterior doors may only solve some of your customer’s needs. Dual or crossover types of key control exist that allow one key to fit all locks. The high security or restricted key will pass standard and high security locks, allowing it to act as a master key or sub-master. The standard keys will still work the low security interior locks.

What does the customer need? Who needs to go where? Not all employees need a front door key. By consulting with the customer and asking the questions who, how, and where, you’ll uncover their specific needs. Then, you the locksmith professional will have the necessary customer input to determine the proper level of security for your customer.