Abstract: A system (200) detects transmission of potentially malicious packets. The system (200) receives, or otherwise observes, packets and generates hash values based on variable-sized blocks of the packets. The system (200) then compares the generated hash values to hash values associated with prior packets. The system (200) determines that one of the received packets is a potentially malicious packet when one or more of the generated hash values associated with the received packet match one or more of the hash values associated with the prior packets.

Abstract: A system (200) detects transmission of potentially malicious packets. The system (200) receives, or otherwise observes, packets and generates hash values based on variable-sized blocks of the packets. The system (200) then compares the generated hash values to hash values associated with prior packets. The system (200) determines that one of the received packets is a potentially malicious packet when one or more of the generated hash values associated with the received packet match one or more of the hash values associated with the prior packets.

Abstract: A system (120) detects transmission of potentially unwanted e-mail messages. The system (120) may receive e-mail messages and generate hash values based on one or more portions of the e-mail messages. The system (120) may then determine whether the generated hash values match hash values associated with prior e-mail messages. The system (120) may determine that one of the e-mail messages is a potentially unwanted e-mail message when one or more of the generated hash values associated with the e-mail message match one or more of the hash values associated with the prior e-mail messages.

Abstract: A system (200) detects transmission of potentially malicious packets. The system (200) receives, or otherwise observes, packets and generates hash values based on variable-sized blocks of the packets. The system (200) then compares the generated hash values to hash values associated with prior packets. The system (200) determines that one of the received packets is a potentially malicious packet when one or more of the generated hash values associated with the received packet match one or more of the hash values associated with the prior packets.

Abstract: Disclosed are systems and methods that can be used to detect shooters. The systems and methods described herein use arrival times of a shockwave, produced by a shot, at a plurality of sensors to assign weights to each of the plurality of sensors, and determine a shot trajectory based on the assigned weights.

Abstract: A system (200) detects transmission of potentially malicious packets. The system (200) receives, or otherwise observes, packets and generates hash values based on variable-sized blocks of the packets. The system (200) then compares the generated hash values to hash values associated with prior packets. The system (200) determines that one of the received packets is a potentially malicious packet when one or more of the generated hash values associated with the received packet match one or more of the hash values associated with the prior packets.

Abstract: A system (126-129) detects transmission of potentially malicious packets. The system (126-129) receives packets and generates hash values corresponding to each of the packets. The system (126-129) may then compare the generated hash values to hash values corresponding to prior packets. The system (126-129) determines that one of the packets is a potentially malicious packet when the generated hash value corresponding to the one packet matches one of the hash values corresponding to one of the prior packets and the one prior packet was received within a predetermined amount of time of the one packet. The system (126-129) may also facilitate the tracing of the path taken by a potentially malicious packet. In this case, the system (126-129) may receive a message that identifies a potentially malicious packet, generate hash values from the potentially malicious packet, and determine whether one or more of the generated hash values match hash values corresponding to previously-received packets.

Abstract: A system (120) detects transmission of potentially unwanted e-mail messages. The system (120) may receive e-mail messages and generate hash values based on one or more portions of the e-mail messages. The system (120) may then determine whether the generated hash values match hash values associated with prior e-mail messages. The system (120) may determine that one of the e-mail messages is a potentially unwanted e-mail message when one or more of the generated hash values associated with the e-mail message match one or more of the hash values associated with the prior e-mail messages.

Abstract: A system and method for performing source path isolation in a network. The system comprises an intrusion detection system (IDS), a source path isolation server (SS1) and at least one router configured to operate as a source path isolation router (SR1) operating within an autonomous system. When IDS detects a malicious packet, a message is sent to SS1. SS1 in turn generates a query message (QM) containing at least a portion of the malicious packet. Then, QM is sent to participating routers located one hop away. SR1 uses the query message to determine if it has observed the malicious packet by comparing it with locally stored information about packets having passed through SR1. SR1 sends a reply to SS1, and SS1 uses the reply to identify the ingress point into the network of the malicious packet.

Abstract: A system and method for performing source path isolation in a network. The system comprises an intrusion detection system (IDS), a source path isolation server (SS1) and at least one router configured to operate as a source path isolation router (SR1) operating within an autonomous system. When IDS detects a malicious packet, a message is sent to SS1. SS1 in turn generates a query message (QM) containing at least a portion of the malicious packet. Then, QM is sent to participating routers located one hop away. SR1 uses the query message to determine if it has observed the malicious packet by comparing it with locally stored information about packets having passed through SR1. SR1 sends a reply to SS1, and SS1 uses the reply to identify the ingress point into the network of the malicious packet.

Abstract: A system and method for identifying target packets in a network. The invention identifies packets by computing a hash value over at least a portion of a packet passing through a network device such as a router. The hash value is used as an address, or index, into a memory. The hash value identifies a unique memory address and a flag is set at the respective memory location. When a target packet is detected elsewhere in a network, the network device receives a query message containing a hash value of the target packet. The network device compares the target packet to the hash values in memory. A match between the hash value in memory and the hash value in the query message indicates the target packet was observed by the network device. After a match is detected, the network device makes a reply available to the network.

Abstract: A system (200) detects transmission of potentially malicious packets. The system (200) receives, or otherwise observes, packets and generates hash values based on variable-sized blocks of the packets. The system (200) then compares the generated hash values to hash values associated with prior packets. The system (200) determines that one of the received packets is a potentially malicious packet when one or more of the generated hash values associated with the received packet match one or more of the hash values associated with the prior packets.

Abstract: A system (126-129) detects transmission of potentially malicious packets. The system (126-129) receives packets and generates hash values corresponding to each of the packets. The system (126-129) may then compare the generated hash values to hash values corresponding to prior packets. The system (126-129) determines that one of the packets is a potentially malicious packet when the generated hash value corresponding to the one packet matches one of the hash values corresponding to one of the prior packets and the one prior packet was received within a predetermined amount of time of the one packet. The system (126-129) may also facilitate the tracing of the path taken by a potentially malicious packet. In this case, the system (126-129) may receive a message that identifies a potentially malicious packet, generate hash values from the potentially malicious packet, and determine whether one or more of the generated hash values match hash values corresponding to previously-received packets.

Abstract: A system (120) detects transmission of potentially unwanted e-mail messages. The system (120) may receive e-mail messages and generate hash values based on one or more portions of the e-mail messages. The system (120) may then determine whether the generated hash values match hash values associated with prior e-mail messages. The system (120) may determine that one of the e-mail messages is a potentially unwanted e-mail message when one or more of the generated hash values associated with the e-mail message match one or more of the hash values associated with the prior e-mail messages.

Abstract: A system (120) detects transmission of potentially unwanted e-mail messages. The system (120) may receive e-mail messages and generate hash values based on one or more portions of the e-mail messages. The system (120) may then determine whether the generated hash values match hash values associated with prior e-mail messages. The system (120) may determine that one of the e-mail messages is a potentially unwanted e-mail message when one or more of the generated hash values associated with the e-mail message match one or more of the hash values associated with the prior e-mail messages.

Abstract: A system (120) detects transmission of potentially unwanted e-mail messages. The system (120) may receive e-mail messages and generate hash values based on one or more portions of the e-mail messages. The system (120) may then determine whether the generated hash values match hash values associated with prior e-mail messages. The system (120) may determine that one of the e-mail messages is a potentially unwanted e-mail message when one or more of the generated hash values associated with the e-mail message match one or more of the hash values associated with the prior e-mail messages.

Abstract: Shockwave-only solutions that estimate shooter position and shot trajectory are extremely sensitive to the quality and precision of the shock time-of-arrival (TOA) measurements as well as the accuracy to which relative sensor positions in space are known. Over the life of a long-deployed system, the sensor positions can shift and the performance of some sensors may degrade for various reasons. Such changes can degrade the performance of deployed shooter estimation systems. Disclosed are systems and methods that can be used to calibrate sensor positions based on shock and muzzle measurements processed from a series of shots fired from a known location and in a known direction, as well as an approach for dynamically adapting shock-only shooter estimation algorithms to compensate for sensor degradation and/or loss.

Abstract: Systems and methods for locating the shooter of supersonic projectiles based on shockwave-only measurements are described. Muzzle blast signals are neither sought nor required. The system uses at least five, preferably seven, acoustic sensors that are spaced apart at least 1 meter. The sensor signals are acquired with a time resolution in the order of microseconds and processed to find and disambiguate the shockwave arrival angle unit vector. Two different Time-Difference-Of-Arrival (TDOA) measurement techniques are described, with one technique using counters in each signal channel and the other technique using cross-correlation between signal channels. A genetic algorithm can be used to efficiently disambiguate the results.

Abstract: A system (120) detects transmission of potentially unwanted e-mail messages. The system (120) may receive e-mail messages and generate hash values based on one or more portions of the e-mail messages. The system (120) may then determine whether the generated hash values match hash values associated with prior e-mail messages. The system (120) may determine that one of the e-mail messages is a potentially unwanted e-mail message when one or more of the generated hash values associated with the e-mail message match one or more of the hash values associated with the prior e-mail messages.