Showing papers on "Handshake published in 2003"

Effectiveness of RTS/CTS handshake in IEEE 802.11 based ad hoc networks

Abstract: IEEE 802.11 MAC mainly relies on two techniques to combat interference: physical carrier sensing and RTS/CTS handshake (also known as “virtual carrier sensing”). Ideally, the RTS/CTS handshake can eliminate most interference. However, the effectiveness of RTS/CTS handshake is based on the assumption that hidden nodes are within transmission range of receivers. In this paper, we prove using analytic models that in ad hoc networks, such an assumption cannot hold due to the fact that power needed for interrupting a packet reception is much lower than that of delivering a packet successfully. Thus, the “virtual carrier sensing” implemented by RTS/CTS handshake cannot prevent all interference as we expect in theory. Physical carrier sensing can complement this in some degree. However, since interference happens at receivers, while physical carrier sensing is detecting transmitters (the same problem causing the hidden terminal situation), physical carrier sensing cannot help much, unless a very large carrier sensing range is adopted, which is limited by the antenna sensitivity. In this paper, we investigate how effective is the RTS/CTS handshake in terms of reducing interference. We show that in some situations, the interference range is much larger than transmission range, where RTS/CTS cannot function well. Two independent solutions are proposed in this paper. One is a simple enhancement to the IEEE 802.11 MAC protocol. The other is to utilize directional antennas. Simulation results verify that the proposed schemes indeed can help IEEE 802.11 resolve most interference caused by large interference range.

Transport Layer Security (TLS) Extensions

Abstract: This document describes extensions that may be used to add functionality to Transport Layer Security (TLS). It provides both generic extension mechanisms for the TLS handshake client and server hellos, and specific extensions using these generic mechanisms.

Secure network processing

Abstract: In one general aspect, a network communication unit is disclosed that includes a cryptographic record parsing offload engine that has an input and an output. The unit also includes a processor that includes cryptographic handshake logic and has an input operatively connected to the output of the cryptographic record parsing offload engine.

The Invisible Handshake: The Reemergence of the State in the Digital Environment

Abstract: The article examines shifts in the role of the State in the information environment, and focuses on the recent, innovative, cooperation between the State and private parties. We argue that while assuming the role of a regulator, the State allowed private nodes of control to emerge and develop in the information environment. We describe how the regulatory regime of the 1990s facilitated this process. When the State now seeks to seize control in the information environment it utilizes these private nodes of control to combat terror. The invisible hand turned out to be very useful for the State, and it is now replaced with a handshake between the State and the private sector. It too, is invisible. The article seeks to make the invisible handshake visible, identifying the legislation that enables the State to seize control in the decentralized borderless information environment. The article traces this intriguing process of recruiting private parties for governing tasks, and analyzes its ramifications for the Internet.

Method and system for secure alert messaging

Abstract: An alert messaging system and method to securely transmit and receive alert messages via secure connection among one or more messaging servers and at least one client user station using a token-based, one-way handshake mechanism.

Control system and control method, method and apparatus for processing information, information processing terminal and method thereof, storage medium, and program

Abstract: A client (such as a PC, portable telephone, PDA, electrical appliances), to which a device such as a IC card is connected, starts a handshake protocol to request a server to start communication. When communication is established via the handshake protocol, the initiative of communication is transferred to the server, and the state changes into a neutral state. In this neutral state, a control packet including a particular number of messages and a finished message is transmitted from the server to the client. If the client receives the control packet, the client performs a process according to the messages included in the control packet. This makes it possible to remotely control a device via a network in a highly reliable and efficient manner.

Data network based telephone messaging system

Abstract: A sending device exchanges handshake signals with a recording device prior to the delivery of voice messages. The sending and recording device are remotely connected using a data network. In one embodiment of the present invention, the data network provides different levels of quality of services (QOS). The voice message can be sent using a low QOS level that permits long delays between voice-based data packets. On the other hand, the handshaking negotiation (e.g., the status request and acknowledgment packets) is carried out using a higher QOS level that permits shorter delays. By knowing the status of the recording device before recording, a user will not waste time to record the voice message.

Translation of secure communications for handshake protocols

Abstract: Systems and methods of the invention provide translation of secure communications for handshake protocols. A system is provided that includes a first client application, a server application, and a translation component. The first client application is configured to transmit and receive communications via a network. The server application configured to receive queries from at least one client application via the network and to transmit responses to at least one client application via the network. The translation component is configured to receive communications from the first client application and translate the received communications into queries that are understandable to the server application.

Synchronous Full-Scan for Asynchronous Handshake Circuits

Abstract: Handshake circuits form a special class of asynchronous circuits that has enabled the industrial exploitation of the asynchronous potential such as low power, low electromagnetic emission, and increased cryptographic security. In this paper we present a test solution for handshake circuits that brings synchronous test-quality to asynchronous circuits. We add a synchronous mode of operation to handshake circuits that allows full controllability and observability during test. This technique is demonstrated on some industrial examples and gives over 99% stuck-at fault coverage, using test-pattern generators developed for synchronous circuits. The paper describes how such a full-scan mode can be achieved, including an approach to minimize the number of dummy latches in case latches are used in the data path of the handshake circuit.

Method and system for reducing interferences due to handshake tones

Abstract: A method and system of the present inventions reduces both NEXT and FEXT interferences due to handshake tones into upstream and downstream neighboring services, both at the CPE and at the CO, when handshake is experienced. An embodiment of the present inventions is directed to significantly reduce the NEXT and/or FEXT interferences due to handshake tones. For example, NEXT and/or FEXT interferences due to G.994.1 handshake tones, identified as, bins 7 and 9 for the Upstream channel and bins 12, 14 and 64 for the Downstream channel may be reduced. An embodiment of the present inventions provides an algorithm that may be used for both NEXT and FEXT Handshake Interferences reduction at the CO and at the CPE. In addition, the algorithm may operate in the time domain and in the frequency domain. Frequency domain algorithm offers two options, both versions taking advantage of the high correlation time of the Handshake tone signals.

A WTLS handshake protocol with user anonymity and forward secrecy

Abstract: Forward secrecy and user anonymity are provided in the WTLS for the wireless Internet communications. Forward secrecy can be built by using Diffie-Hellman key agreement with random numbers in the Hello messages, and user anonymity by employing the signcryption scheme to the ClientKeyExchange and CertificateVerify procedure. In addition to these features, the modified WTLS handshake protocol has mutual authentication and key agreement against man-in-the-middle attacks. The resulting security features, bandwidth efficiency, and computational load are analyzed in comparison with the existing WTLS.

Handshake protocol using return-to-zero data encoding for high performance asynchronous bus

Abstract: In SoC design, synchronous buses are used frequently to interconnect several IPs. However, it is difficult to use synchronous buses for SoC design because of the increase of wire delay caused by the crosstalk effect and the difficulty of synchronisation caused by the clock-skew problem. The use of an asynchronous bus is an alternative solution for SoC design methodology. A new handshake protocol is proposed using the return-to-zero data encoding scheme for the implementation of a new high performance asynchronous bus. Simulation results reveal that the proposed handshake protocol increases the read throughput of the asynchronous bus by 30.5%, and decreases the read latency by 12.5%.

Reduced symbol rate handshake signaling in ADSL systems

Abstract: In an asynchronous digital subscriber line (ADSL) system comprising a central office High Speed ADSL Terminating Unit (HSTU-C) in bi-directional discrete multitone (DMT) communication with a remote High Speed ADSL Terminating Unit (HSTU-R), a method for improving handshake detection is provided by the present invention. The method comprises transmitting handshake signaling from the HSTU-C to the HSTU-R via a first subset of carrier sets at a first symbol rate and transmitting handshake signaling from the HSTU-C to the HSTU-R via a second subset of carrier sets at a second symbol rate, the second symbol rate being less than the first symbol rate.

Data communication system and method

Abstract: A data communications method and system is disclosed in which the transmission control protocol (TCP) is used for data communications. In order to provide security against denial of service attacks and the like, a connection negotiation phase is required before the TCP handshake. Without a successful connection negotiation, a TCP handshake is unable to complete thereby preventing connection.

DSL communication apparatus, and download method of DSL communication program

Abstract: A host manages a ROM that stores a handshake program for executing a handshake sequence and an initialization program for executing an initialization sequence During the handshake sequence, the handshake program is retrieved from the ROM to download the program to a non-resident memory of a program area Upon completing the handshake sequence, the initialization program is retrieved from the ROM, to download the program to the non-resident memory, replacing the handshake program

A new robust handshake for asymmetric asynchronous micro-pipelines

Abstract: In this paper, a new handshake methodology to enhance the performance of the asynchronous micro-pipeline systems is proposed. The proposed handshake methodology has more flexibilities to design an asymmetric asynchronous micro-pipeline system. The proposed handshake methodology also has some advantages, like latch free, robust, high throughput, very short pre-charge time, less transistors, and more flexibility in asymmetry data path. A technique that combines a single-rail dynamic circuit with a dual-rail dynamic circuit was proposed and used to design in the data path. In the critical delay data paths, the dual-rail dynamic circuits were used to improve the operating speed. Others, the single-rail dynamic circuits were used. It brings some advantages that reduce power consumption and die area while maintaining the calculation speed. An asynchronous micro-pipeline array multiplier was designed and implemented by the new robust handshake methodology. Based on the TSMC 0.35/spl mu/m CMOS technology, the simulation results show that the proposed new handshake methodology has shortest latency and more robust property as compare with other handshake methodologies.

A WTLS handshake protocol with user anonymity and forward secrecy

Abstract: Forward secrecy and user anonymity are provided in the WTLS for the wireless Internet communications. Forward secrecy can be built by using Diffie-Hellman key agreement with random numbers in the Hello messages, and user anonymity by employing the signcryption scheme to the ClientKeyExchange and CertificateVerify procedure. In addition to these features, the modified WTLS handshake protocol has mutual authentication and key agreement against man-in-the-middle attacks. The resulting security features, bandwidth efficiency, and computational load are analyzed in comparison with the existing WTLS.

A robust handshake for asynchronous system

Abstract: In this paper, a new handshake methodology to enhance the performance of the asynchronous systems is proposed. The proposed handshake methodology has more flexibility to design an asymmetric asynchronous system. The proposed handshake methodology also has some advantages, like latch free, robust, high throughput, very short pre-charge time, less transistors, and more flexibility in asymmetry data path. A technique that combines a single-rail dynamic circuit with a dual-rail dynamic circuit was proposed and used to design in the data path. In the critical delay data paths, the dual-rail dynamic circuits were used to improve the operating speed. In others the single-rail dynamic circuits were used. It brings some advantages that reduce power consumption and die area while maintaining the calculation speed. Finally, an asynchronous array multiplier was designed and implemented by the new robust handshake methodology. Based on the TSMC 0.35 /spl mu/m CMOS technology, the simulation result of the maximum throughput is about 2.5 ns.

Universal bridge control structure

Abstract: PURPOSE: A universal bridge control structure is provided to offer a data communication interface between blocks used in arranging SOCs(System On Chip), specially for interfacing data asynchronously between the blocks irrespective of a clock. CONSTITUTION: The structure comprises a handshake control block, a ring oscillator block, and a synchronization module. The ring oscillator block generates local clocks and transmits the local clock to the synchronization block if a handshake signal like a request signal or an acknowledge signal is input from the handshake control block. The ring generator block, a kind of a clock generator, is chained by inverters, and can determine an inverter stage according to a client request. The clock is generated by using a phase locked loop.

Handshake protocol conversion logic circuit and input/ output interface circuit for asynchronous lsi chip

Abstract: PROBLEM TO BE SOLVED: To reduce the time required for one time data transfer to the half at maximum. SOLUTION: In this input/output interface circuit for an LSI chip for packaging a 4-cycle bundle data transfer system asynchronous circuit, at the time of outputting data to the outside of the chip, a handshake protocol is converted from 4-cycle to 2-cycle by a logic circuit 130, and at inputting data from the outside of the chip, the handshake protocol is converted from 2 cycle to 4 cycle by a logic circuit 140. COPYRIGHT: (C)2003,JPO

System for automatically configuring a transceiver as either a central or a remote unit in a communication system

Abstract: The present invention allows a transceiver unit to freely and automatically choose whether it will operate as a central unit or as a remote unit, depending on the capabilities of the peer transceiver unit, which it is connected to. The transceiver unit listens first to any signal the peer may transmit to initiate the handshake procedure. Such a signal would de-facto identify the peer as a remote unit or as a central unit and would allow the transceiver unit to select the appropriate role. If no signal is detected, the transceiver unit tries to initiate the handshake procedure and waits for the corresponding signal from the peer. In a first embodiment, the transceiver unit tries to initiate the handshake procedure as a remote unit only. In a second embodiment, the transceiver unit tries to initiate the handshake procedure both as a central unit and as a remote unit.