Connecting a Classified Network to the Internet. A case study.

A classified (computer) network is one that stores information that is sensitive and should not be made available to the general public. The purpose of this document is to point out some common elements from the guidelines published to regulate computer security and suggest administrative action and technical solutions to build a network that may be connected to the Internet, and still obtain/retain a classification up to and including NATO RESTRICTED. The author is not aware of any standard that will allow a system classified at NATO CONFIDENTIAL or higher to be connected to a public network (Internet). Note that the standards mentioned (BS7799, ITSEC, CommonCriteria a.s.o.) only tell what to achieve, not how.