Changhua Zhu

AMS Based Reconstruction Algorithm with Two-dimensional Threshold for IP Traceback

In this paper we present a new reconstruction algorithm. This algorithm is based on the Advanced Marking Scheme (AMS), and it works with a two-dimensional threshold mfd decides if a node is on the attack path by judging the situation of the edge of the packet and the Hash value match, then consequently reduces the time of reconstruction and overhead and improves the accuracy. Simulation results from the experiments carried on in the network test-bed show that obtained results are the same as theoretical results. Performance analysis and simulation experiment results shows, compared with the conventional methods, two-dimensional threshold reconstruction algorithm improves the performance of IP traceback technique obviously.

Polarization-Encoding-Based Measurement-Device-Independent Quantum Key Distribution with a Single Untrusted Source

Measurement-device-independent quantum key distribution (MDI-QKD) can be immune to all detector side-channel attacks and guarantee the information-theoretical security even with uncharacterized single photon detectors. MDI-QKD has been demonstrated in both laboratories and field-tests by using attenuated lasers combined with the decoy-state technique. However, it is a critical assumption that the sources used by legitimate participants are trusted in MDI-QKD. Hence, it is possible that a potential security risk exists. Here we propose a new scheme of polarization-encoding-based MDI-QKD with a single untrusted source, by which the complexity of the synchronization system can be reduced and the success rate of the Bell-state measurement can be improved. Meanwhile, the decoy-state method is employed to avoid the security issues introduced by a non-ideal single photon source. We also derive a security analysis of the proposed system. In addition, it seems to be a promising candidate for the implementation for QKD network in the near future.

Quantum secret sharing without monitoring signal disturbance

Secret sharing, in which a dealer wants to split a secret in such a way that any unauthorized subsets of parties are unable to reconstruct it, plays a key role in cryptography. The security of quantum protocols for the task is guaranteed by the fact that Eve’s any strategies to obtain secret information from encoded quantum states should cause a disturbance in the signal. Here, we propose a quantum secret sharing (classical information) scheme for N parties which is no longer needed to monitor signal disturbance. Comparing to existing qudit-based schemes, this scheme has obvious advantages in feasibility and scalability. Our work paves a novel way for quantum secret sharing.

Effects of atmospheric turbulence on the single-photon receiving efficiency and the performance of quantum channel with the modified approximate elliptic-beam model assumption

In free space quantum channel, with the introduction and implementation of the satellite-ground link transmission, the researches of single-photon transmission have attracted great interest. We propose a single-photon receiving model and analyze the influence of the atmospheric turbulence on the single-photon transmission. We obtain the relationship between single-photon receiving efficiency and atmospheric turbulence, and analyze the influence of the atmospheric turbulence on the quantum channel performance by the single-photon counting. Finally, we present a reasonable simulation analysis. Simulation results show that as the strength of the atmospheric fluctuations increases, the counting distribution gradually broadens, and the utilization of quantum channel drops. Furthermore, the key generation rate and transmission distance decreases sharply in the case of strong turbulence.

Quantum Bit Commitment Combining with BB84 Protocol

We proposed a new quantum bit commitment scheme in which secret key need not to be provided by other quantum key distribution system. We can get the bit commitment with probability p by adding a waiting time in a frame during operating the BB84 protocol. Then the measurement outcomes can be encrypted by one-time pad with the key generated by BB84 protocol. We can also obtain the redundant secret keys to encrypt other information in this quantum key distribution system.

Improved Efficient Priority-and-Activity-Based QoS MAC Protocol

Wireless network has significantly affected human life. MAC protocols which already existed mostly transmit data without priority so that emergency event data cannot be sent quickly to destination nodes. In this paper, a new protocol called priority-and-activity-based QoS MAC (PAQMAC) protocol is proposed, in which not only the priority of data in transmission is considered, but also the active time is dynamical adjusted by recording the activity degree in a duty cycle. With the priority classified, it provides enough time to deal with emergency event, thus the security and management of network are also improved. Simulation results show that PAQMAC protocol can reduce transmission delay and decrease energy consumption of network.

Performance evaluation of acquisition algorithm for BOC-modulated signal against interference

In this paper, we analyze the characteristics of frequency spectrum and autocorrelation function of the signal in global navigation satellite system (GNSS) with binary offset carrier (BOC) modulation. We discuss the basic working processes of the traditional BOC acquisition algorithm and the one by using auto-correlation side-peak cancellation technique (ASPeCT). We also evaluate the effect of eliminating secondary peak and anti-interference performance of these two algorithms. We perform the simulation under Gaussian white noise and band-limited white noise. The simulation results show that the acquisition algorithm by ASPeCT has great advantage in the effect of side-peak cancellation and few advantages in anti-interference performance in Gaussian white noise and band-limited white noise environments.

Research and implementation of high-speed aviation bus

Since traditional aviation bus gradually can not meet the needs of modern military communication, migration of aviation bus towards high speed transmission is arousing wide concern. This paper purposes a method for improving throughput and transmission rate of the aviation bus while reserving legacy devices. In addition to cost, the logistics of implementing this upgrade to an aircraft can be prohibitive based on the amount of time required to retrofit an entire fleet. Moreover, the method combines OFDM (Orthogonal Frequency Division Multiplexing) modulation and aviation network has been evaluated over MIL-STD-1553 bus. The maximum rate can achieve 22Mbit/s. It shows a considerable performance improvement and meets the requirements of avionic high-rate communication.

Study on Network Topology Visualization Algorithm and Implement Based on A Algorithm

This paper presents a network topology visualization algorithm based on A* algorithm. This algorithm is not only very universally applicable which can improve greatly the speed of operation and save the memory and meet the real-time requirement of network topology visualization, but also solve the problem of loop caused by single topology visualization algorithm, therefore, it’s preferably suitable for the research on complicated network topology.

Active Probe of Available Bandwidth: Analysis and Improvement

Active probe is the main method for Internet end-toend available bandwidth estimation. Based on the analysis of packet gap in active probing, an improved method to estimate available bandwidth is proposed, which is based on the concept of self-induced congestion. In this method, the transmission rates of probe packets are increased step by step and a new decision criteria, NWID (Normalized Weighted Increased Delay), is defined. Another idea is that sliding-window decision is adopted to obtain the available bandwidth in one measurement. Simulation and test results show that the measurement precision is improved with slightly adding probing overhead compared with pathChirp.