一种新的隐蔽通信算法

近年来,在通信领域隐蔽通信技术正越来越受到重视.本文提出了一种新的实时隐蔽通信算法,该算法利用了混沌序列具有容易生成、对初始条件敏感,以及具有白噪声的统计特性等特点,有效地解决了隐蔽通信技术的两个问题:同步以及突发信息的接收.实验结果表明这种算法是非常有效的.     

一种基于图像的无损隐秘传输方法

提出了一种新的基于预测编码的图像无损隐秘传输方法.该方法用线性预测误差扩展和嵌入/提取算法,在图像无损编码压缩过程中嵌入大数据量的秘密信息,提取秘密信息后,原宿主图像信息能无损恢复.该方法已在局域网上进行了实验,结果表明,与以往的无损嵌入算法相比,其提高了秘密信息的可嵌入容量,且对隐藏信息后的图像质量影响较小.     

基于神经网络的隐写图像盲检测系统设计

将秘密信息隐藏在图像中通过网络传输是当前一种十分流行的隐蔽通信手段。针对隐写图像的检测国际上已经公布了许多检测算法。本文在分析这些算法局限性的基础上利用BP神经网络方法来设计图像盲检测系统。其目的是在没有原图像载体的条件下提高发现网络中的隐写图像的准确率。最后本文简要给出了基于神经网络的隐写图像设计要点、实现框图和优缺点。     

一种卫星隐蔽通信信号盲分离算法

重构抵消算法是卫星隐蔽通信信号分离的关键技术,算法的性能主要依赖于参数估计的精度。然而在实际环境中,参数估计误差带来的算法性能损失无法被避免。此外,对信号的重构使得该算法计算复杂度较高。针对这个问题,首先分析了参数估计误差对分离性能的影响,然后提出基于盲均衡算法的协作分离算法,提升信号分离性能的同时降低了算法的计算量。仿真实验表明,新算法相较于重构抵消算法,降低了对参数估计精度的依赖,当参数估计误差大于0.05时,信号的解调误码率降低了一个数量级左右。     

一种新颖的消噪算法及其在通信中的应用

本文提出了一种自适应变窗长平滑滤波的消噪算法,它依据信号在小波变换域和时域的幅度分布特性,把信号分成特性不同的时间片段,然后按片段信号的特性采用自适应变窗长平滑滤波的方法,对经过内插处理后的高采样率信号进行消噪处理.这种方法非常适合分段连续或分段平稳信号的消噪处理,仿真结果表明该算法具有良好的性能.本文将该算法应用于扩频通信系统中脉冲干扰的消除,仿真结果说明这种算法与脉冲置零法相比,性能得到了较大的改善.     

一种基于机器学习的卫星重叠隐蔽通信方法

针对传统卫星重叠通信中单个掩护信号带宽以及功率容限不够的问题,利用卫星转发器频谱环境中多个掩护信号提出了一种频域分割-子谱功率控制联合优化的多掩护信号重叠通信方法,建立了隐蔽通信信号传输性能和隐蔽性能的双目标优化问题,信关站侧采用感知的历史频谱数据训练生成支持向量机回归预测模型,用来预测不同转发器频谱环境下隐蔽信号的通信性能和隐蔽性能,并将训练好的预测模型下载到通信终端;终端侧利用双目标背包算法将支持向量机回归预测模型预测的隐蔽信号的通信性能和隐蔽性能作为价值因素、掩护信号个数作为背包重量来选择转发器频谱环境中的掩护信号,并且求解出隐蔽信号的频域分割和子频谱的功率控制参数,从而实现终端通信信号隐藏在卫星转发器的频谱环境中的目的。     

无人机中继协助的有限码长隐蔽通信

由于中长距离的无线隐蔽通信中信号发射功率较大,容易被监测者检测到,针对此问题该文提出无人机(UAV)中继协助的有限码长隐蔽传输方案。首先,根据无人机通信的信道模型,推导从发射机经过无人机中继到合法接收机的信噪比(SNR),得到隐蔽传输中断概率及吞吐量的表达式;然后,分析监测者的检测性能, 即KL(Kullback-Leibler)散度,并将其作为隐蔽通信的约束条件;最后,在此约束的条件下,联合优化发射机和中继的发射功率以及无人机的飞行高度,从而最大化隐蔽通信的吞吐量。仿真结果验证了系统的隐蔽性能,并且通过与缺少无人机协助的传统方案对比,揭示所提出的无人机中继隐蔽传输方案可以有效地降低监测者的KL散度。     

面向隐蔽双站反向散射网络的性能优化

针对双站反向散射通信（Backscatter Communication,BackCom）网络易遭受恶意窃听的问题,提出了隐蔽双站BackCom网络。推导了窃听者检测错误概率和BackCom传输中断概率来刻画其信息传输的隐蔽性与可靠性,并提出一种方法在满足隐蔽性约束下来进一步提高系统的传输性能。利用统计信道状态信息,在高信噪比条件下依次推导窃听者检测错误概率BackCom中断概率的闭合表达式。通过联合优化窃听者的检测阈值和BackCom发射机的反射系数,构建一个BackCom传输中断概率最小化的非凸多维资源分配问题。为了解决该非凸问题,采用块坐标下降法（Block Coordinate Descent,BCD）将其分解为两个子问题。在此基础上,深入分析子问题的结构特性并利用目标函数关于反射系数的单调递减特性设计一种基于BCD的迭代算法,以此求解转换问题。仿真结果验证了分析结果的正确性并且所提方案能够提升基准方案的性能,当传输速率为0.1 Mb/s时,系统的中断概率能够降低至10-2;对于较大传输速率,系统的中断概率仍保持在10-1以下。     

一种安全高效的组播源认证一次签名方案分析

基于一次签名的认证应用很广，通常的方法有在线，离线签名和前向安全的签名，但组播环境下的高效签名方案极为少见。这里提出了一种一次签名方案，它是一种对于签名生成和签名验证都极为高效的方案，而且签名长度很短。特别适用于组播通信的数据源认证。     

基于VoIP隐蔽通信的实现方法

信息隐藏作为一门新兴的信息安全技术最近受到人们的普遍关注。文章选择VoIP作为信息隐藏的载体,研究了基于VoIP的隐蔽通信的实现方法。首先分析了基于VoIP隐蔽通信技术的特征和优点;提出了VoIP隐蔽通信的实现过程的模型和多种隐蔽信道;最后介绍了基于VoIP的隐蔽通信软件的实现算法。     

一种可隐藏敏感文档和发送者身份的区块链隐蔽通信模型

目前,区块链隐蔽通信的研究主要是通过发起多笔交易来传输一条短消息,这一方式不仅不适用于敏感数据量大的情况,还可能存在有些交易没有被打包而造成秘密信息的丢失,而且传输过程没有隐藏发送方身份.部分区块链隐蔽通信的研究中使用的图像隐写术虽然具有嵌入率高这一优点,但是越来越难以抵御基于统计特征的检测分析.针对以上问题,本文提出...     

An Efficient Pre-Traceback Architecture for the Viterbi Decoder Targeting Wireless Communication Applications

A large portion of silicon area and the energy consumed by the Viterbi decoder (VD) is dedicated to the survivor memory and the access operations associated with it. In this work, an efficient pre-traceback architecture for the survivor-path memory unit (SMU) of high constraint length VD targeting wireless communication applications is proposed. Compared to the conventional traceback approach which is based on three kinds of memory access operations: decision bits write, traceback read, and decode read, the proposed architecture exploits the inherent parallelism between the decision bit write and decode traceback operation by introducing pre-traceback operation. Consequently, the proposed pre-traceback approach reduces the survivor memory read operations by 50%. As a result of the reduction of the memory access operations, compared to the conventional 2-pointer traceback algorithm, the size of the survivor memory as well as the decoding latency is reduced by as much as 25%. Implementation results show that the pre-traceback architecture achieves up to 11.9% energy efficiency and 21.3% area saving compared to the conventional traceback architecture for typical wireless applications.     

A One-Time Pad Encryption Scheme Based on Efficient Physical-Layer Secret Key Generation for Intelligent IoT System

The one-time pad(OTP) is an applicationlayer encryption technique to achieve the informationtheoretic security, and the physical-layer secret key generation(SKG) technique is a promising candidate to provide the random keys for OTP. In this paper, we propose a joint SKG and OTP encryption scheme with the aid of a reconfigurable intelligent surface(RIS) to boost secret key rate. To maximize the efficiency of secure communication, we divide the process of secure transmission into two stages: SKG a...     

物理层隐蔽通信的检测和性能分析

隐蔽通信是指在无线通信过程中,利用隐蔽技术使监测人无法检测到无线传输的存在,使得信息在传递过程中受攻击的风险大大降低。论文主要研究物理层隐蔽通信的检测方法和性能分析,首先,在现有隐蔽通信研究的基础上归纳出物理层隐蔽通信的理论框架;其次,阐述了看守者的检测度量方法及其检测性能分析;第三,以文献比较的方式对隐蔽通信的性能和仿真结果的评价进行了分析,最后,总结了一些撰写本文时未解决的技术挑战,并讨论了隐蔽通信的未来趋势。     

基于客户端蜜罐的木马隐蔽通信检测

当今流行的木马程序开始采用隐蔽通信技术绕过蜜罐系统的检测。首先介绍木马常用的隐蔽通信技术以及越来越流行的内核层Rootkit隐蔽通信技术,并讨论了现阶段客户端蜜罐对于恶意程序的检测方式。针对蜜罐网络通信检测机制的不足,提出了一种有效的改进方案,使用基于NDIS中间层驱动的网络数据检测技术来获取木马通信数据包。该方案能够有效检测基于网络驱动的Rootkit隐蔽通信,提取木马关键通信信息,以进行对木马行为的跟踪和分析。     

Security Against Covert Adversaries: Efficient Protocols for Realistic Adversaries

In the setting of secure multiparty computation, a set of mutually distrustful parties wish to securely compute some joint function of their private inputs. The computation should be carried out in a secure way, meaning that no coalition of corrupted parties should be able to learn more than specified or somehow cause the result to be “incorrect.” Typically, corrupted parties are either assumed to be semi-honest (meaning that they follow the protocol specification) or malicious (meaning that they may deviate arbitrarily from the protocol). However, in many settings, the assumption regarding semi-honest behavior does not suffice and security in the presence of malicious adversaries is excessive and expensive to achieve. In this paper, we introduce the notion of covert adversaries, which we believe faithfully models the adversarial behavior in many commercial, political, and social settings. Covert adversaries have the property that they may deviate arbitrarily from the protocol specification in an attempt to cheat, but do not wish to be “caught” doing so. We provide a definition of security for covert adversaries and show that it is possible to obtain highly efficient protocols that are secure against such adversaries. We stress that in our definition, we quantify over all (possibly malicious) adversaries and do not assume that the adversary behaves in any particular way. Rather, we guarantee that if an adversary deviates from the protocol in a way that would enable it to “cheat” (meaning that it can achieve something that is impossible in an ideal model where a trusted party is used to compute the function), then the honest parties are guaranteed to detect this cheating with good probability. We argue that this level of security is sufficient in many settings.     

有序多重签名体制中阈下信道通信方法的研究

本文分析了阈下信道技术在数字签名中的应用，并以一种有序多重数字签名方案为例，对其中存在的宽带和窄带阈下信道进行了具体分析．提出了一种有序多重签名体制下的窄带阈下信道通信方案，通过实时性测试确定阈下信息位数，从而满足了传输信息容量与实时性的要求。     

A Survey on Deep Learning-Based Vehicular Communication Applications

Journal of Signal Processing Systems - Besides the use of information transmission, vehicular communications also perform an essential role in intelligent transportation systems (ITS) for...     

Experience Sampling Method Applications to Communication Research Questions

The Experience Sampling Method (ESM) is a quasi-naturalistic method that involves signaling research subjects at random times throughout the day, often for a week or longer, and asking them to report on the nature and quality of their experience. The method has been applied to an increasing number of research problems in medicine, the social sciences, and communication. In this essay, the authors, who have developed the methodology over the past 20 years, reflect on some of the methods applications within communication studies. The ESM is contrasted with traditional questionnaire and diary methods, and its value in mapping behavior's ecological context and the nature of human experience is assessed. The authors suggest how the method can be applied to research problems in organizational settings, such as work and schools; with regard to mass and mediated communication; and to interpersonal, familial, and marital communication topics