ZEMAX is copy-protected by a
Safenet Sentinel Hardware Key, which is available in standalone and network-licensed versions, and is plugged into the USB port of a computer:

The Sentinel Hardware Key token is a proprietary security device which is used by a specific application to ensure that each user of the application has the rights to run the application. At no time does any other application, part of the Operating System or system user have access to the key's 8 kb memory, nor can the key's memory be used as a generic storage area. The only way to use the key's memory is through SafeNet specific APIs, and with a specifically protected application.
These keys are purchased from SafeNet pre-programmed with the serial number which is also engraved on each key. ZEMAX Development Corporation then programs a code that identifies the key as being eligible to run the SE or EE versions of ZEMAX.
Obsolete Key Types
ZEMAX previously used Sentinel SuperPro devices. These devices are no longer supplied, but are still currently supported, although support will be phased out at some future date. Keys with current support may be exchanged for the new type at no charge.
If these keys are being used in highly secure environments, we recommend that they be replaced with the new type, by
following these instructions.