What are site codes or families? And, how are they used?

Sites codes, or families, were originally created to increase card production to a larger number of 26-bit cards by duplicating cards rather than increasing the available number of user codes. The cards were ordered for a specific site and the manufacturers were initially keeping track of what had been shipped where. When a new site was installed, it was provided with a site code that had never been shipped to that specific geographical area, thus maintaining the level of security of the card. Furthermore, since all the cards at a specific site had the same site code, the control equipment did not have to store the site code in each of the user codes, reducing memory requirements of the hardware.

As the market for access control exploded, it became almost impossible to maintain such a strategy. Although some manufacturers still work this way (the change represents considerable modifications to both hardware and software), the trend is to provide cards with a greater number of bits, making obsolete the notion of site codes. This new method also enables faster delivery of cards, even for add-ons to existing sites, right out of the manufacturer's or the distributor's regular stock. As long as the card number is unique, just like serial numbers on currency bills, security is maintained. Manufacturers should all be requested to provide a written statement certifying that their cards are unique and will never be duplicated. Kantech's ioProx, ShadowProx and HID-KSF cards are guaranteed to be unique and never duplicated!