Abstract: A method of detecting intrusions on a computer includes storing an intrusion signature describing an attack on a computer. Once a plurality of internet protocol packets is received, the plurality of internet protocol packets collectively containing an information sequence within a series of states, it is rearranged so as to place the information sequence in order. Each state of the series of states is then successively examined so as to correlate the information sequence to the intrusion signature.

Abstract: A method of detecting intrusions on a computer includes the step of identifying an internet protocol field range describing fields within internet protocol packets received by a computer. A connectivity range is also established which describes a distribution of network traffic received by the computer. An internet protocol field threshold and a connectivity threshold are then determined from the internet protocol field range and connectivity range, respectively. During the operation of the computer, values are calculated for the internet protocol field range and connectivity range. These values are compared to the internet protocol metric threshold and connectivity metric threshold so as to identify an intrusion on the computer.

Abstract: A method of forming a virtual intrusion detection system includes the step of positioning a set of sensors in a network environment, each sensor supporting multiple logical traffic paths. The method also includes the step of providing a set of sensor management systems corresponding to the set of sensors. This set of sensor management systems enforces a set of virtual intrusion detection systems, wherein each virtual intrusion detection system corresponds to a predetermined logical traffic path through the set of sensors, each virtual detection system providing sensor traffic information solely to authorized parties.

Abstract: A method of provisioning a computer against computer attacks includes constructing a hierarchy characterizing different computer attacks and counter measures, and traversing this hierarchy to identify computer attacks and countermeasures relevant to a target platform. Detection and protection measures are collected in response to this traversing. These detection and protection measures are then downloaded to a security sensor associated with the target platform.