Abstract: Intrusion protection. A first packet en route to a first destination is received. A first value representing a benefit for analyzing the first packet for intrusions in relation to a cost for analyzing the first packet for intrusions is automatically determined. An automatic determination is made that the first value is sufficiently high to warrant an analysis of the first packet for intrusions, and in response, the first packet is analyzed for intrusions. If the analysis of the first packet for intrusions indicates an intrusion, the first packet is discarded without forwarding the first packet to the first destination. A second packet en route to a second destination is received. A second value representing a benefit for analyzing the second packet for intrusions in relation to a cost for analyzing the second packet for intrusions is automatically determined.

Abstract: Protecting computer networks by altering unwanted network data traffic. An Intrusion Protection System (IPS) or an Intrusion Detection System (IDS) can monitor network data traffic comprising byte information. This network security device analyzes network data traffic at the byte level to determine whether an intrusion event is present in the network data traffic. If an intrusion event is detected, the network security device alters at least a portion of the relevant byte information to prevent the occurrence of a successful intrusion event at the intended destination. This altered byte information is then passed to the destination by the network security device. If an intrusion event is not present, the network security device passes the byte information without alteration to the destination.