The characteristics of underwater acoustic channel such as long propagation delay and low bit rate cause the MAC(Medium Access Control) protocols designed for radio channels to be either inapplicable,or have low effic...The characteristics of underwater acoustic channel such as long propagation delay and low bit rate cause the MAC(Medium Access Control) protocols designed for radio channels to be either inapplicable,or have low efficiency for UWSN(Underwater Sensor Network).We propose a hierarchical and distributed code assignment algorithm based on divisive probability function which can avoid conflict between spread codes with high probability,and provide a statebased MAC protocol for UWSN.Without RTS/CTS(Request To Send/Clear To Send) handshaking,each node maintains a neighbor table including state field,and packages are forwarded according to the state of the receiver,so it can avoid the interference caused by transmitting to a sending node in a half-duplex system and improve channel utilization.The design of power control minimizes the nearfar effect inherent in CDMA.Simulation results reveal that state-based CDMA protocol shows outstanding performance in throughput,delivery ratio and resource-consumption.展开更多
A novel video data authentication model based on digital video watermarking and MAC （message authentication code） in multicast protocol is proposed in this paper, The digital watermarking which composes of the MAC o...A novel video data authentication model based on digital video watermarking and MAC （message authentication code） in multicast protocol is proposed in this paper, The digital watermarking which composes of the MAC of the significant vid eo content, the key and instant authentication data is embedded into the insignificant video component by the MLUT （modified look-up table） video watermarking technology. We explain a method that does not require storage of each data packet for a time, thus making receiver not vulnerable to DOS （denial of service） attack. So the video packets can be authenticated instantly without large volume buffer in the receivers. TESLA （timed efficient stream loss tolerant authentication） does not explain how to select the suitable value for d, which is an important parameter in multicast source authentication. So we give a method to calculate the key disclosure delay （number of intervals）. Simulation results show that the proposed algorithms improve the performance of data source authentication in multicast.展开更多
CAN(Controller Area Network)总线技术的发展令人惊叹,基于CAN的车载总线实现ECU(Electronic Control Unit)分布式实时数据通讯,自由通信,总线仲裁。本文提出了在CAN协议基础上增加ECU间(Key)密钥分配与信息认证,简称MAC(Message Authe...CAN(Controller Area Network)总线技术的发展令人惊叹,基于CAN的车载总线实现ECU(Electronic Control Unit)分布式实时数据通讯,自由通信,总线仲裁。本文提出了在CAN协议基础上增加ECU间(Key)密钥分配与信息认证,简称MAC(Message Authentication Code,信息认证码)。本文会由浅入深阐述当前CAN总线协议基础上的MAC的工作原理与实现方式。展开更多
基金supported by the Program for New Century Excellent Talents in University of China(NCET-11-1025)the NationalNatural Science Foundation of China(No.61162003,61163050,6126104)+1 种基金Qinghai office of science and technology(grant No.2012-Z-902)the Natural Science Foundation of Tianjin(No.10JCYBJC00600)
文摘The characteristics of underwater acoustic channel such as long propagation delay and low bit rate cause the MAC(Medium Access Control) protocols designed for radio channels to be either inapplicable,or have low efficiency for UWSN(Underwater Sensor Network).We propose a hierarchical and distributed code assignment algorithm based on divisive probability function which can avoid conflict between spread codes with high probability,and provide a statebased MAC protocol for UWSN.Without RTS/CTS(Request To Send/Clear To Send) handshaking,each node maintains a neighbor table including state field,and packages are forwarded according to the state of the receiver,so it can avoid the interference caused by transmitting to a sending node in a half-duplex system and improve channel utilization.The design of power control minimizes the nearfar effect inherent in CDMA.Simulation results reveal that state-based CDMA protocol shows outstanding performance in throughput,delivery ratio and resource-consumption.
基金Supported bythe National Natural Science Foundationof China (60175001)
文摘A novel video data authentication model based on digital video watermarking and MAC （message authentication code） in multicast protocol is proposed in this paper, The digital watermarking which composes of the MAC of the significant vid eo content, the key and instant authentication data is embedded into the insignificant video component by the MLUT （modified look-up table） video watermarking technology. We explain a method that does not require storage of each data packet for a time, thus making receiver not vulnerable to DOS （denial of service） attack. So the video packets can be authenticated instantly without large volume buffer in the receivers. TESLA （timed efficient stream loss tolerant authentication） does not explain how to select the suitable value for d, which is an important parameter in multicast source authentication. So we give a method to calculate the key disclosure delay （number of intervals）. Simulation results show that the proposed algorithms improve the performance of data source authentication in multicast.
文摘CAN(Controller Area Network)总线技术的发展令人惊叹,基于CAN的车载总线实现ECU(Electronic Control Unit)分布式实时数据通讯,自由通信,总线仲裁。本文提出了在CAN协议基础上增加ECU间(Key)密钥分配与信息认证,简称MAC(Message Authentication Code,信息认证码)。本文会由浅入深阐述当前CAN总线协议基础上的MAC的工作原理与实现方式。
