DEFENSE IN DEPTH

Defense in depth is the concept of protecting a computer network with a series of defensive mechanisms such that if one mechanism fails, another will already be in place to thwart an attack. Because there are so many potential attackers with such a wide variety of attack methods available, there is no single method for successfully protecting a computer network. Utilizing the strategy of defense in depth will reduce the risk of having a successful and likely very costly attack on a network. This paper will look at three common scenarios for network attacks, likely methods of attack, and countermeasures to protect the network from the attacks. The first scenario is an attack by a script kiddie from the Internet, the second is an attack from a skilled hacker and the final attack is from a trusted user who has access to the network. This paper does not attempt to provide a comprehensive discussion of who attackers are, the methods they use in their attacks, or methods to protect against the attacks. A work of that sort would fill volumes and is obviously far beyond the scope or intention of this essay.