The flood-gate principle - a hybrid approach to a high security solution

The classical role of a firewall consists in protec ting a computer network against attacks from the outside world, espe cially the Internet. Firewalls are often expensive, hard to configure and they are comprehended only by experts. Sometimes the level of security is t oo high to use a firewall, and information flow has not to be "online". Here we prop ose to use "flood- gates" as described in the following. They provide a modern , simple and easy- to-understand method to secure a network on a very high se curity level. E- mails, plain files and all sorts of electronic data can be exchanged over such flood-gates without possibly compromising the "own" network by the most dangerous classes of attacks. Information passes through the flood-gates even though there is not a single moment of a physically conne ction between the own network and the outside world. The disadvantage of service restrictions can be overcome by a multilevel security approach. As a pr actical example a concrete "real-life" implementation of the flood-gate principle in the financial sector is described in detail in this paper.