One embodiment is described of a method performed by a computing device for renewing a remote token. The method includes (a) receiving an activation code from the remote token across a network, the activation code including an identification of the token, (b) verifying that the activation code was cryptographically generated with reference to a one-time passcode (OTP) generated by the identified token using an initial key assigned to the token, and (c) in response to verifying, negotiating a new key with the token, the new key to be assigned to the token for use in producing OTPs in the future. Related computer program products, systems, and apparatuses are also described.

Automated token renewal using OTP-based authentication codes

The invention discloses a time synchronization method of a master-slave structure multi-node network Two clock synchronization mechanisms of a response type mechanism and a broadcast type mechanism are designed aiming at the condition that nodes of the network are physically connected through wires, and the communication between the nodes is performed through RS485, RS422, RS232, CAN bus modes Accurate sending and receiving times of each message can be obtained through FPGA clock sampling The transmission average delay and the master-slave clock offset are calculated through a response type synchronization mode, and the time precision is compensated and the time synchronization with the nanosecond grade high precision is reached The time synchronization with the higher precision can be reached when the channel transmission time delay is ignored through a broadcast type synchronization mode

Time synchronization method of master-slave structure multi-node network

Some embodiments herein include at least one of systems, methods, and devices for power-efficient data transfer between two communicating devices. The two devices establish two wireless links between each other; the first link using a low-power/low-throughput protocol and utilized to maintain a second link, the second link using a high-power/high-throughput protocol. When first device data is available for transmission, the first device instructs the second device via the first link to switch to the second link for data reception. The first device then transmits data to the second device via the second link. When the transmission is complete, both devices switch back to using the first link to maintain their connection to each other. In some embodiments, the first device may be a Human Interface device and the second device may be a Bluetooth controller of a computing device.

Wireless communication device and method for power-efficient data transfer

The invention discloses a time synchronization method and a time synchronization system for synchronous messages of IEEE1588 master-slave clocks of an intelligent transformer substation. The method comprises the following steps of: establishing a master clock synchronous message, and sending the timestamp t1 of the sending moment of the message to the clock in a broadcasting manner; recording a receiving moment t2 of the master clock synchronous message; recording an absolute receiving moment TT2 when the master clock synchronous message is received by a slave clock; establishing a slave clock responding message, sending the slave clock responding message to the master clock in a peer-to-peer manner, and recording the timestamp t3 of the sending moment of the message; recording an absolute sending moment TT3 when the slave clock sends the clock responding message; recording an acquiring moment t4 when the master clock acquires the message; calculating a time deviation, and calculating asymmetry errors according to the timestamp t1, the absolute receiving moment TT2, the absolute sending moment TT3 and the acquiring moment t4; and carrying out time correction on the slave clock by the time deviation and the asymmetry errors. According to the time synchronization method and the time synchronization system for synchronous messages of IEEE1588 master-slave clocks of the intelligent transformer substation, the influences of the asymmetry errors can be eliminated, and the time synchronization precision of the master-slave clocks is improved.

Time synchronization method and system for synchronous messages of IEEE1588 (Precision Time Protocol) master-slave clocks of intelligent transformer substation

One embodiment is directed to a method performed by a computing device. The method includes (a) engaging in a handshake procedure with a remote second computing device to establish a secure channel, (b) generating a first encryption key using a first token having a secret seed, the first encryption key being the same as a second encryption key generated by the second computing device using a second token having the same secret seed, and (c) using the first encryption key to engage in encrypted communications with the second computing device. Other embodiments are directed to a computerized apparatus and a computer program product for performing a method similar to that described above.

Token-based key generation

The invention discloses a method for realizing accurate time synchronization by utilizing an IEEE1588 protocol, comprising the following steps: a) a Sync message is transmitted to a slave clock by a master clock, a transmission timestamp TM1 and a receiving timestamp TS1 of the message are acquired by the slave clock; b) a Delay_Req message is transmitted to the master clock by the slave clock, and a transmission timestamp TM2 and a receiving timestamp TS2 of the message are acquired by the slave clock; c) transmission delay and time offset are calculated by the slave clock according to the timestamp; and d) the calculated Offset is corrected in a fixed adjustment frequency in the correction time by the slave clock. The invention realizes accurate time synchronization, calculates time offset and self-compensate through the slave time clock in a packet based network, and leads the slave clock to lock the master clock whether in clock frequency or on the clock time in a shorter time, and occupies little hardware resources.

Method for realizing accurate time synchronization by utilizing IEEE1588 protocol

A method, a device and a system for clock synchronization are provided. The method includes: under a first transfer mode, generating a first receiving timestamp by using a first link, and acquiring a first transmitting timestamp of a master clock device; under a second transfer mode, generating a second transmitting timestamp by using the first link, and acquiring a second receiving timestamp of the master clock device; and acquiring a time difference to the master clock device according to the first receiving timestamp, the first transmitting timestamp, the second transmitting timestamp and the second receiving timestamp, and realizing a clock synchronization with the master clock device by using the time difference. A slave clock device and a master clock device are provided in the embodiments of the present invention, as well as a system for clock synchronization.

Method, device and system for clock synchronization

The invention provides a clock synchronization method, clock synchronization equipment and a clock synchronization system. The method comprises the following steps of: in a first transmission mode, generating a first receiving timestamp by using a first link and acquiring a first transmitting timestamp of master clock equipment; in a second transmission mode, generating a second transmitting timestamp by using the first link and acquiring a second receiving timestamp of the master clock equipment; and according to the first receiving timestamp, the first transmitting timestamp, the second transmitting timestamp and the second receiving timestamp, acquiring a time deviation with the master clock equipment; and realizing clock synchronization with the master clock equipment through the time deviation. The embodiment of the invention provides slave clock equipment and the master clock equipment. The embodiment of the invention also provides the clock synchronization system. The method, the equipment and the system realize the uniformity of message round trip links between the master clock equipment and the slave clock equipment, and ensure the symmetry of uplink delay and downlink delay.

Clock synchronization method, equipment and system

The invention discloses an ad hoc network routing method based on the label circular shift of an MAC layer. The method comprises the following steps: (a) when a source node transmits a data packet, putting routing information comprising labels in an address field of an MAC frame, putting the data packet in a body field of the MAC frame and then sending out the MAC frame; (b) if the address field in the data packet received by an intermediate node only comprises one label, taking out the data packet in the body field of the MAC frame and transmitting the data packet upward to an IP layer and completing the transmission of the data packet; if the address field comprises more than one label, shifting all the labels in the address field circularly and then transmitting the MAC frame to a nodecorresponding to a first label in the address field after circular shift; and (c) carrying out the operation step (b) circularly until completing the transmission of the data packet. In the invention, the ad hoc network routing method carries label routing by the address field of the MAC frame, thereby transmitting the data packet only by the MAC of the intermediate node instead of the IP layer, and enhancing the network performance greatly.

Ad hoc network routing method based on label circular shift of MAC layer

PRIME is a solution for Powerline Communications in the CENELEC A-Band using OFDM modulation. SFN can be applied to PRIME system to take advantage of the repeater effect of PHY nodes in the SFN to achieve dynamic routing. Synchronization algorithm of SFN-aided PRIME system is detailly studied and anylized. The false alarm probability of synchronization algorithm is also derived. Simulation results shows that choosing proper threshold and correlation window length can get good synchronization performance.

Yunfeng Liu

Papers

Method for realizing accurate time synchronization by utilizing IEEE1588 protocol

Method, device and system for clock synchronization

Clock synchronization method, equipment and system

Ad hoc network routing method based on label circular shift of MAC layer

Synchronization of SFN-aided PRIME narrowband PLC system