Abstract: The invention computes approximate origins of data packets transmitted over the Internet. Law enforcement agencies and network operators can use it to assign responsibility for observed Internet activities. The invention uses a small number of cooperative locations (incoming links on routers or switches) to provide link identification data: whether a packet or did or did not traverse that location. The system uses these cooperative places to generate the link signature of a data packet—which cooperative locations observed and did not observe the packet. Potential origin locations are divided into pre-computed blocks that have the same link signatures to given destination locations. The blocks are used to generate reverse routing data, potential source addresses for different link signatures. Variations of the invention store relevant link identification and reverse routing data to find the origins of past packets or to compute the origins of packets from partial information about packets of interest.

Abstract: The invention computes approximate origins of data packets transmitted over the Internet. Law enforcement agencies and network operators can use it to assign responsibility for observed Internet activities. The invention uses a small number of cooperative locations (incoming links on routers or switches) to provide link identification data: whether a packet or did or did not traverse that location. The system uses these cooperative places to generate the link signature of a data packet—which cooperative locations observed and did not observe the packet. Potential origin locations are divided into pre-computed blocks that have the same link signatures to given destination locations. The blocks are used to generate reverse routing data, potential source addresses for different link signatures. Variations of the invention store relevant link identification and reverse routing data to find the origins of past packets or to compute the origins of packets from partial information about packets of interest.

Abstract: The invention prevents “packet flooding”, where an attacker uses up all available bandwidth to a victim with useless data. It can also be used to prevent some other related denial of service attacks. The defense is distributed among cooperating sites and routers. The sites identify data they don't want. The routers help sites to determine which routers forward that data. The sites then ask these routers to reduce the rate at which such data is forwarded. Variations of the defense protect against packet flooding attacks on routers and attacks in which an attacker tries to use up some service offered by a site.

Abstract: The invention prevents “packet flooding”, where an attacker uses up all available bandwidth to a victim with useless data. It can also be used to prevent some other related denial of service attacks. The defense is distributed among cooperating sites and routers. The sites identify data they don't want. The routers help sites to determine which routers forward that data. The sites then ask these routers to reduce the rate at which such data is forwarded. Variations of the defense protect against packet flooding attacks on routers and attacks in which an attacker tries to use up some service offered by a site.

Abstract: The invention prevents “packet flooding”, where an attacker uses up all available bandwidth to a victim with useless data. It can also be used to prevent some other related denial of service attacks. The defense is distributed among cooperating sites and routers. The sites identify data they don't want. The routers help sites to determine which routers forward that data. The sites then ask these routers to reduce the rate at which such data is forwarded. Variations of the defense protect against packet flooding attacks on routers and attacks in which an attacker tries to use up some service offered by a site.

Abstract: The invention is designed to eliminate or minimize the liability associated with “packet flooding” attacks originating from within a local area network connected to an external network such as one controlled by a university or governmental organization. In these attacks, an attacker uses up all available bandwidth to a victim with useless data. The invention performs its function by identifying and classifying data packets arriving at a “Reverse Firewall” for transmission to the external network using various techniques. For example, data packets that are sent in response to data packets received from the external network will receive a different classification and thus allocation of resources than data packets not sent in response to previously received packets.