Patent ID: 7500264
Filing Date: 2009-03-03
Classification: H04L

Abstract:
1. In an intrusion detection system, a method of blocking attacks on a computer network, comprising: receiving, in circuitry of the intrusion detection system, original packets and corresponding retransmit packets from a network, wherein: hashing, in the circuitry of the intrusion detection system, said non-mutable field values of each said original packet to produce a validation signature of each said original packet; storing, in the circuitry of the intrusion detection system, said validation signatures; hashing, in the circuitry of the intrusion detection system, said non-mutable field values of each said corresponding retransmit packet to produce a test signature of each said corresponding retransmit packet; comparing, in the circuitry of the intrusion detection system, said validation signature to said test signature; and if said test signature and said validation signature are not identical, terminating said flow by operating a flow terminator circuit of the intrusion detection system.