To accomplish this same effect in your network, consider deploying multiple firewalls protecting sensitive network segments - those belonging to finance, human resources or other departments, for example. That way, even if a hacker manages to break into your network he or she won't be able to do much while there. Of course, installing multiple layers of protection can be a hassle for legitimate employees, and this is the trade-off any network administrator faces when implementing a security infrastructure. On one side is security and confidentiality, and on the other side is ease of use and simplicity. Using passwords in conjunction with smartcards containing digital certificates unique to each employee, workers prove their identity at log-on while providing a digital certificate that individual applications can use to query digital certificate authorities until they are satisfied that the employee has presented valid identification.
Access control is just one part of security, however.
Such technology provides a valuable backup to ensure that any users sneaking through firewalls can still be monitored on the network. No matter how careful you are, the important thing to remember is that there will always be another hacker online who'd like to break into your network. As in many things, vigilance is the key.