Computer-based products such as postal security devices are manufactured as generic, nondescript units. Each has a unique identifier or embedded hardware serial number readable by data communications such as serial electrical communications. At customization time, a human-readable marking is placed on the device, along with a bar code indicative of the human-readable marking. A bar-code reader reads the bar code. The embedded hardware serial number is read. A record is made in a database indicative of the embedded hardware serial number and the bar code information. Software may then be selected based on the bar code information, and loaded into the device, typically within a cryptographically secure area within the device. At a later time the device may be retired from service and reprogrammed, in which case a new human-readable marking and bar code are affixed to the device. The embedded hardware serial number and new bar code information are read and appropriate new data records are created. The data records may further contain information regarding cryptographic keys loaded into the device and version levels of software within the device. In this way a generic device may be customized and efficiently managed.