Digital Locks / eCylinder TutorialBy: Brian Rhodes, Published on Feb 07, 2012
In some applications ‘traditional’ panel/controller based Electronic Access Control are difficult to justify the total cost. After the costs of hardware, cabling, installation, and training are all tallied, it is not uncommon to spend upwards of $2500 USD per controlled opening (i.e. door, gate, entry, etc...). This can quite simply prove to be too expensive to consider, no matter the need.
In other applications, installation of the prevalent form factor Access Control equipment (Controller Panels, Power Supplies, Card Readers, etc) may be difficult or impossible. In still other cases (such as records storage cabinets or controlled substance carts), there might be a need to indeed ‘control access’ only to the same degree that keys and locks already provide, but provide additional features such as scheduling controls and audit trails against the opening.
In this gray area of the market, the ‘Digital Lock’ has gained attention. ‘Digital Locks’ are also commonly identified by branding such as ‘eCylinders’, ‘Mul-T-Lock’ [link no longer available], ‘LOGIC’ [link no longer available], ‘CLIQ [link no longer available]’, ‘NEXGEN XT’ or by more common nomenclature such as ‘electro-mechanical locks’, ‘chip locks’, ‘smart locks’, or ‘RFID locks’ – which in some cases might be a misnomer.
In the Door Hardware market, there are relatively few conglomerates that own huge portions of the industry; corporations like Ingersoll Rand, ASSA ABLOY, and Stanley are among this group. ‘Digital Locks’, as a merchantable product in the market, seem to be driven by various ASSA ABLOY offerings (lead by the ‘high security’ brand MEDECO) at this point in time. It is unclear whether or not the other ‘big names’ in this market will choose to pursue similar products in the same form factor.
While exact feature sets may vary, in general the ‘digital lock’ is partnered with a specialized accompanying key. The lock itself remains unpowered, or is powered by the introduction of the key into the keyway from a power source built into the key. Most often, a dual authentication is required to resolve the lock – first, an encoded credential handshaking takes place between the key and the lock, and secondly, with a valid permission, the lock will permit itself to be opened in the traditional manner by rotation of the key.
These products remain substantially similar to mechanical locks, but have the additional layer of proximity or contact encoding that must be resolved first. The key must be properly logically credentialed, and also cut to match to the bitting of the lock, or the key will not resolve the lock.
The image below shows the basic 'look' of these locks:
Advantages of a 'Digital Lock' system
The most significant advantage of this method of controlling access appears to be the rather low cost of retrofitting existing openings (i.e. door, gate, entry, etc...) with only new locking hardware vs. the implementation of full-blown electronic access control hardware. The form factors of these ‘digital locks’ match the hardware already deployed – mortise cylinders, ICC systems, rim cylinders, knobs, cam locks, cabinet locks, showcase locks, and padlocks all have ‘digital lock’ retrofit units available. This means that a simple exchange of hardware is all that is required to gain the enhanced functionality. This cost is normally anywhere from $85 to $850 USD depending on the product/form factor, and does not require any modification to the opening, auxilary hardware, or utility to implement.
A log of activity against each lock and/or key is stored in nonvolatile memory onboard each component. Commonly, up to 5000 events can be stored for download to a central database when opportunity permits. This ‘audit trail’ feature not only records successful openings, but unsuccessful attempts as well.
Disadvantages of a 'Digital Lock' system
The ability to make a key valid only during a certain schedule, or to otherwise make a key invalid, is a mainstay function of EAC. This feature is also possible with ‘digital lock’ systems. However, a marked disadvantage vs. traditional EAC is that, in order to completely invalidate a key, each previously resolvable lock must be updated with new settings via physical interaction with those locks. While this may not prove to be a challenge for some deployments, needing to continuously update lock scheduling (commonly through the insertion of a ‘programming key’) just isn’t a practical constraint for many larger deployments with many doors or many locks.
Another marked disadvantage of ‘digital lock’ systems are the comparatively high costs of the key vs. traditional ‘card based’ EAC systems. Proximity cards can often be issued for less than $5 USD, while a ‘digital lock’ key can cost $80+ USD, and still need to be mechanically cut in order for use. While blank inactive cards may be commonly available in the market, the source of supplying keys is highly restricted and limited by design.