Abstract: Respective nodes N1 to N3 only detect a carrier, and the node N3 sets a random time between a time after a certain period of time t1 and a time until a certain period of time t2 after the carrier of data D11 is gone as a waiting time so as to transmit data within this waiting time. The node N2 transmits ACK data D12 with respect to the data D11 to the node N1 before the certain period of time t1 after the carrier of the data D11 is gone. The node N3 detects the carrier of the ACK data D12 and again sets a random time after the certain period of time t1 until the certain period of time t2 to transmit the data.

Abstract: Nodes (N1 to N3) include MTU length calculation sections (31 to 33) which multiply baud rates (D21 to D23) of communication parameters (D11 to D13) set based on results of negotiation with other nodes (N1 to N3) by a communication regulated time used in timer control for transmission/reception, and which calculate MTU lengths as maximum packet lengths of the packets based on the multiplication results so that transmission times of the packets for the destination nodes are equal to each other, and also include communication control sections (21 to 23) which divide data to be transmitted to destination nodes into packets having the calculated MTU length to transmit the packets.

Abstract: To obtain a remote authentication system that securely authenticates with protecting biometrics information, which is user's personal information, and is firm on security when performing authentication of a person with the biometrics information, and a remote authentication method. The present invention encrypts biometrics information that is user's personal information, and transfers the biometrics information over a network in such a state that only an authentication server, which the user assigns, can decode the biometrics information. Therefore, it is possible to securely protect user's privacy that is the biometrics information in a style of reflecting user's intention, and to prevent reuse of invalid authentication information since it is possible to confirm the date and time, when the authentication information was generated, by the authentication server.

Abstract: The communication system conducts communication among nodes N1 to N4 that form a communication network of bus type by using set communication parameters. The communication system includes one master node N1 selected from among the nodes N1 to N4; and one or more slave nodes N2 to N4 that are nodes N2 to N4 other than the master node N1, the one or more slave nodes logically star-connected to the master node N1, each of the one or more slave nodes conducting communication with another node N2 to N4 via the master node N1 by using communication parameters negotiated with the master node N1.

Abstract: Nodes (N1 to N3) include MTU length calculation sections (31 to 33) which multiply baud rates (D21 to D23) of communication parameters (D11 to D13) set based on results of negotiation with other nodes (N1 to N3) by a communication regulated time used in timer control for transmission/reception, and which calculate MTU lengths as maximum packet lengths of the packets based on the multiplication results so that transmission times of the packets for the destination nodes are equal to each other, and also include communication control sections (21 to 23) which divide data to be transmitted to destination nodes into packets having the calculated MTU length to transmit the packets.

Abstract: Respective nodes N1 to N3 only detect a carrier, and the node N3 sets a random time between a time after a certain period of time t1 and a time until a certain period of time t2 after the carrier of data D11 is gone as a waiting time so as to transmit data within this waiting time. The node N1 transmits ACK data D12 with respect to the data D11 to the node N12 before the certain period of time t1 after the carrier of the data D11 is gone. The node N3 detects the carrier of the ACK data D12 and again sets a random time after the certain period of time t1 until the certain period of time t2 to transmit the data.

Abstract: An encryption apparatus enables encrypted communications using existing network equipment which does not have an encryption function, such as a server, a client, or a router. The encryption apparatus is connected to a section between a terminal and a network, data from the terminal is encrypted and sent to the network, data from the network is decrypted and sent to the terminal, and a connection control frame between the terminal and the network is not encrypted.

Abstract: A transmitting-receiving unit or a set of upper rank transmitting-receiving units and lower rank transmitting-receiving units are provided, and one or a plurality of circuits selected by a circuit selective switch unit from among many circuits are connected to the transmitting-receiving unit or the set. As a result, the burden of the control unit provided in the communication device is reduced. The maintenance of a route table which is used in transmitting packets from the highest rank station to the lowest rank station via other communication devices is made unnecessary by transferring the route table in order from the highest rank stations to the lowest rank stations.