Abstract: A detection system includes an obtainer that obtains a first log, the first log being a log of communication in a first network; a determiner that determines whether the first log obtained by the obtainer includes anomaly information indicating anomalous communication in a second network; and a controller that, when the determiner has determined that the first log includes the anomaly information, performs control of notifying of an anomaly in the second network.

Abstract: A method of the Virtual Private Network (VPN) communication employed for a security gateway apparatus and the security gateway apparatus using the same, which allow a personal computer outside a local area network (LAN) to access, via a WAN, to a terminal on the LAN, virtually regarding the outside PC as a terminal on the LAN. The communication method is employed for a security gateway apparatus to connect, through concentration and conversion process, between a LAN and a WAN including a public network. Security Architecture for the Internet Protocol (IPsec) establishes VPN with an outside PC having a dialup connection to the WAN. During an Internet Key Exchange (IKE) communication that is performed prior to the IPsec communication, the security gateway apparatus integrates a Dynamic Host Configuration Protocol (DHCP) communication option into an IKE data, and designates the IP address of the outside PC from a tunneled IP packet.

Abstract: A household device installed in a house is connected to an open-type connectionless network from the outside. The household device establishes a connection through the network and maintains it by transmitting data packets continuously to a network server within a certain period of time. A user terminal outside the house gains access to the household device through the network server.

Abstract: A method of the Virtual Private Network (VPN) communication employed for a security gateway apparatus and the security gateway apparatus using the same, which allow a personal computer outside a local area network (LAN) to access, via a WAN, to a terminal on the LAN, virtually regarding the outside PC as a terminal on the LAN. The communication method is employed for a security gateway apparatus to connect, through concentration and conversion process, between a LAN-and a WAN including a public network. Security Architecture for the Internet Protocol (IPsec) establishes VPN with an outside PC having a dialup connection to the WAN. During an Internet Key Exchange (IKE) communication that is performed prior to the IPsec communication, the security gateway apparatus integrates a Dynamic Host Configuration Protocol (DHCP) communication option into an IKE data, and designates the IP address of the outside PC from a tunneled IP packet.