Portunus was often portrayed holding a key to a gateway, just as our product requires a secure key for accessing the internal network. All unsafe functions and applications are disabled or removed from the firewall system. Options that could compromise system security are not offered. The system has been designed for mission critical applications using processes and techniques similar to those used by NASA for the software that supports manned space flight. Every function checks its input parameters for reasonability.
Every attempt is made to catch an error before it causes a system failure.
This allows for real time capture and reporting of the problem. If the error has any possibility of compromising the system, the function gracefully shuts down after reporting the problem. The system has an object oriented design that maximizes data hiding and minimizes the use of global variables. Changes can be made to a function without impacting the correct operation of other functions. Security is based on strong user authentication and not by trusting IP addresses as is done with Packet Filtering.