Wormhole Attack Behaviour in Monte-Carlo Localization for Mobile Sensor Networks

Localization is the basic requirement for network management in Wireless Sensor Networks as it helps nodes find their absolute position coordinates and in gathering information relevant to their locations. A localization algorithm has to be dynamic, scalable and should not impose high computation or communication overhead. The localization systems are also prone to attacks. We target a localization scheme for mobile sensor networks called Monte-Carlo Localization, which study its behavior under the most dangerous attack on localization called Wormhole Attack, also known as Collusion Attack and propose a modified algorithm that can help the localization system retain its accuracy level even in the presence of attacks. Our algorithm has communication cost almost equal to that of original localization algorithm (in this case MCL) in the absence of attacks.

Replay Attack and Defense of Electric Vehicle Charging on GB/T 27930-2015 Communication Protocol

The GB/T 27930-2015 protocol is the communication protocol between the non-vehicle-mounted charger and the battery management system (BMS) stipulated by the state. However, as the protocol adopts the way of broadcast communication and plaintext to transmit data, the data frame does not contain the source address and the destination address, making the Electric Vehicle (EV) vulnerable to replay attack in the charging process. In order to verify the security problems of the protocol, this paper uses 27,655 message data in the complete charging process provided by Shanghai Thaisen electric company, and analyzes these actual data frames one by one with the program written by C++. In order to enhance the security of the protocol, Rivest-Shamir-Adleman (RSA) digital signature and adding random numbers are proposed to resist replay attack. Under the experimental environment of Eclipse, the normal charging of electric vehicles, RSA digital signature and random number defense are simulated. Experimental results show that RSA digital signature cannot resist replay attack, and adding random numbers can effectively enhance the ability of EV to resist replay attack during charging.

面向双层传感网的隐私保护k-NN查询处理协议

无线传感器网络作为物联网感知层的核心组成部分,具有广阔的应用前景.然而,隐私泄露问题严重阻碍了传感器网络的发展.目前,传感器网络隐私保护技术已成为研究热点,其中隐私保护κ-NN(κ-Nearest Neighbor)查询协议是富有挑战性的问题.文中提出了面向双层传感器网络的高效的隐私保护κ-NN查询协议.首先,为提升查询效率,基于定向存储策略给出了适用于双层传感网的κ-NN查询架构.其次,针对管理节点俘获攻击,提出了一种新颖的隐私保护数据编码机制,通过为真实数据附加编码的方式,保证在不泄露数据隐私的同时精确地完成查询处理.再次,针对节点共谋攻击,设计了基于代理节点的单向数据隐藏机制,通过破坏普通节点与管理节点间数据的关联性实现抵御共谋攻击的目标.理论分析和仿真实验验证了协议的安全性和有效性.

对一种(t,N-2)弹性Mix Net的密码学分析

分析了Gao等人提出的(t,N-2)弹性Mix Net方案,发现存在严重安全漏洞.主动攻击者利用Elgamal算法的可展性构造具有相关性的密文组,然后通过观察对应明文组的相关性获得输入与输出的对应关系,最终破坏Mix Net的秘密性.两个不同服务器组中的恶意服务器可以相互勾结利用共谋攻击使Mix Net输出错误结果,并以不可忽略的概率逃过验证协议的检验.分析结果说明Gao的方案不满足(t,N-2)弹性,且基于该Mix Net的电子投票应用也是不安全的.

群智感知中基于k-匿名的位置及数据隐私保护方法研究

随着无线智能移动终端设备的爆炸式普及,群智感知应用越来越广泛,是当前的研究热点。然而,用户的隐私泄露问题成为阻碍用户积极参与性的关键因素。基于此,提出一种基于k-匿名的位置及数据隐私保护方法(KPPCS)。首先,采用基于多方安全合作的方法来构造一个包含n个互相没有任何链接的用户的等价类,以保证参与用户的位置隐私。同时,采用数据迭代的方法,使数据在等价类中进行迭代,直到最后一个用户将所有数据上传到服务器,从而确保参与用户数据的隐私性。实验结果及理论分析表明,KPPCS不仅能够保证用户的位置信息及数据所有权信息的安全,且降低了服务器以及用户设备的开销。

运用GD-PBIBD编码的矢量空间数据数字指纹算法

针对矢量空间数据叛逆者追踪难及编码效率低的问题,本文提出了一种运用GD-PBIBD码的指纹算法。首先运用GDPBIBD构造指纹编码,将待嵌入指纹序列运用Logistic映射置乱,通过D-P算法提取矢量空间数据的特征点,对特征点实施DFT变换得到相位系数和幅度系数;然后运用QIM方法将指纹嵌入DFT变换域的幅度系数上;最后应用DFT逆变换得到含指纹的矢量空间数据。试验选取部分中国路网数据和某区域绿地数据,运用该算法嵌入指纹后,对其进行线性和非线性模拟攻击,成功提取指纹序列,利用汉明距离追踪出合谋者。该算法编码构造简单,在码长一定的情况下,较BIBD码可容纳更多的用户,效率高;算法抗单用户指纹攻击及多重攻击的稳健性较好,也能够抵抗多用户最小值和最大最小值攻击,追踪到所有叛逆者,可用于矢量空间数据版权保护,为矢量空间数据叛逆者追踪提供依据。

Effect of nitrite intercalated Mg-Al layered double hydroxides on mortar durability under Cl−and SO_(4)^(2-) coexisting environment

The aim of this paper is to investigate the effect of nitrite intercalated Mg-Al layered double hydroxides(Mg-Al LDH-NO_(2))on mortar durability under the coexisting environment of Cl−and SO_(4)^(2-).Cl−and SO_(4)^(2-) binding properties of Mg-Al LDH-NO_(2) in simulated concrete pore solutions,Cl−and SO_(4)^(2-) diffusion properties of mortars with Mg-Al LDHNO 2 were examined.The steel corrosion and resistance of mortar against SO_(4)^(2-) attack were also evaluated.The results indicate that Mg-Al LDH-NO_(2) can effectively adsorb the Cl−and SO_(4)^(2-) in simulated concrete pore solution,and inhibit the diffusion of Cl−and SO_(4)^(2-) into cement mortars.The presence of SO_(4)^(2-) can greatly affect the uptake amount of Cl−,and there is a coupled effect of Cl−and SO_(4)^(2-) on their penetration into mortar specimens.In addition,Mg-Al LDH-NO_(2) can greatly upgrade the resistance of mortars against SO_(4)^(2-) attack and well prevent the steel from corrosion.However,Cl−will aggravate the SO_(4)^(2-) attack and SO_(4)^(2-) can initially decrease and then increase the steel corrosion.

Cryptanalysis on an organization-friendly blockchain system

To verify that an organization-friendly blockchain system may suffer from forgery and collusion attacks,forgery and collusion attacks were theoretically carried out according to the phase sequence of an organization-friendly blockchain system.Then,the organization-friendly blockchain system was improved and based on the phase sequence forgery and collusion attacks were conducted.The results show that the attacker can obtain illegal transaction data from forgery and collusion attacks on the organization-friendly blockchain system.However,for the improved organization-friendly blockchain,the attacker s forgery and collusion attacks cannot be completed.Therefore,the organization-friendly blockchain system may be subject to forgery and collusion attacks,but the improved organization-friendly blockchain system can prevent such attacks.

A Kind of Multi-party Non-repudiation Protocol with Consistent Evidence

With development of electronic com- merce, non-repudiation protocol as the basal component of non-repudiation service has done more and more important functions. Comparing with lots of work on two-party non-repudiation, there are less work on multi-party non-repudiation protocol. Multi-party protocol is more complex and facing more challenge of collusion attack. In this paper we give a kind of multi-party non-repudiation protocol based on off-line TTP with consistent evidence. Consistent evidence is a property that can not only simplify the process of disputation resolving, but also make the service more friendly to users, which means that whether or not TTP involves, evidences participants obtained are consistent. In the meanwhile we analyze the collusion attack that multi-party protocol facing, our protocol can prevent collusion attack.

A Dual Detection Method for Siemens Inverter Motor Modbus RTU Attack

Since the Modbus RTU wired communication protocol of Siemens variable frequency motors is unstable and lacks a protection mechanism, there is a risk of user information leakage. Aiming at the problems of insufficient flexibility of traditional defense methods and poor defense effects, The present work proposed a new dual detection method based on MODBUS RTU, which combines the dual monitoring mechanism of “Address Resolution Protocol (ARP) request detection” and “ARP response detection”. In order to improve detection efficiency, two real-time updated linear tables are introduced, which can effectively deal with the three ARP spoofing methods of updating the ARP buffer. Based on the analysis of the hidden dangers of the Modbus RTU wired communication protocol, a wired connection between the S7-1200 PLC and the variable frequency motor was established, and a real experimental platform was constructed to demonstrate the attack. The intensity of ARP attacks has gradually increased over time. Through comparative experiments with traditional defense methods, it is proved that the algorithm enhances the protocol mechanism in principle, and is more flexible and reliable than traditional methods.

Improved Multi-party Quantum Key Agreement with Four-qubit Cluster States

Quantum key agreement is a promising key establishing protocol that can play a significant role in securing 5G/6G communication networks.Recently,Liu et al.(Quantum Information Processing 18(8):1-10,2019)proposed a multi-party quantum key agreement protocol based on four-qubit cluster states was proposed.The aim of their protocol is to agree on a shared secret key among multiple remote participants.Liu et al.employed four-qubit cluster states to be the quantum resources and the X operation to securely share a secret key.In addition,Liu et al.’s protocol guarantees that each participant makes an equal contribution to the final key.The authors also claimed that the proposed protocol is secure against participant attack and dishonest participants cannot generate the final shared key alone.However,we show here that Liu et al.protocol is insecure against a collusive attack,where dishonest participants can retrieve the private inputs of a trustworthy participant without being caught.Additionally,the corresponding modifications are presented to address these security flaws in Liu et al.’s protocol.

Development and Application of Al_2O_3-Si_3N_4 Refractories Used in Blast Furnace

Newly developed Al2O3-Si3N4 composite refractories used for blast furnace is introduced in this work. Al2O3-Si3N4 composite refractories attacked by alkali vapor and blast furnace slag was investigated. High performance Al2O3-Si3N4 composite refractories was produced and used at both 2560m^3 blast furnaces of Tan-gsteel and No. 5 blast furnace of Shaosteel.

物联网中多密钥同态加密的联邦学习隐私保护方法

借助联邦学习,多个分布式物联网设备可在不泄露原始数据前提下通过传输模型更新共同训练全局模型.然而,联邦学习系统易受模型推理攻击的影响,导致系统鲁棒性和数据隐私性受损.针对现有联邦学习方案无法实现对共享梯度的机密性保护以及难以抵抗客户端和服务器发起的共谋攻击等问题,提出一种物联网中多密钥同态加密的联邦学习隐私保护方法.该方法利用多密钥同态加密实现了梯度更新机密性保护,首先通过采用代理重加密技术,将不同公钥下的密文转换为公共密钥下的加密数据,确保云服务器实现对梯度密文的解密.然后,物联网设备采用自身的公钥和随机秘密因子加密本地梯度数据,可抵抗恶意设备和服务器发起的合谋攻击.其次,设计了一种基于混合密码体制的身份认证方法,实现对联邦建模参与方身份的实时验证.此外,为了进一步降低客户端计算开销,将部分解密计算协同至可信服务器计算,用户只需少量的计算即可.通过对所提方案进行全面分析以评估其安全性和效率.结果表明,所提方案满足了预期的安全要求.实验仿真表明,该方案相较于现有方案,具有较低的计算开销,可实现更快且准确的模型训练.

一种在原始视频帧中嵌入的鲁棒的数字水印

该文提出的在原始视频帧中的扩频水印方案,使用二值图像作为水印,采用每帧索引的办法,并且利用相邻帧的统计相关性来嵌入水印。对于丢帧、帧重组以及共谋攻击有很强的鲁棒性。水印提取时不需要用到原始视频。文中对该方案进行了详细的介绍,并给出了仿真实验结果。

解决组合公钥共谋攻击和密钥碰撞的新方法

以解决组合公钥体制中共谋攻击和密钥碰撞问题为目的。首先,针对线性共谋攻击,提出了一种新的构造种子矩阵的方法,使得种子密钥和大于基点加法群的阶数,从而使密钥之间不能相互线性表示。其次在密钥的生产过程中,引入系数破坏了层不同和层互斥不同的关系,为解决选择共谋攻击提供了一种有效的方法,同时增强了抵御随机共谋攻击的能力。最后,在密钥产生的流程中,通过公钥对比来避免密钥碰撞,为解决密钥碰撞问题提出了一种新方法。

数字指纹编码与嵌入假设

数字指纹系统是数字水印技术的一个重要分支,是用于盗版追踪的一种技术。离散指纹编码和连续指纹鳊码是数字指纹研究领域的两大阵营。本文介绍了嵌入假设对指纹编码研究的重要意义,指出这两种研究方向的主要分歧在于对待嵌入假设条件的态度不同。从嵌入假设条件出发分析了离散指纹编码和连续指纹编码的基本思路、面临的挑战和发展趋势。

一种双矩阵组合公钥算法

组合公钥算法中存在选择共谋攻击、随机共谋攻击和线性分析共谋攻击.本算法中用户的私钥是基本私钥与辅助私钥的逆元模乘的结果,基本私钥与辅助私钥分别由基本私钥矩阵和辅助私钥矩阵中的元素组合生成,用户的私钥间不存在线性关系.经过分析,本算法可以抵抗组合公钥算法中存在的选择共谋攻击和随机共谋攻击,并且辅助密钥矩阵的大小可以根据需要进行选取,系统的安全性可控.

群签名及其应用

综述了群签名及其应用方面的研究成果及发展状况。分析了现有的群签名方案中所存在的一些缺陷。指出了这方面研究目前所存在的问题及几个值得重视的研究方向。

一种直接评价节点诚信度的分布式信任机制

基于信誉的信任机制能够有效解决P2P网络中病毒泛滥和欺诈行为等问题.现有信任机制大多采用单个信誉值描述节点的诚信度,不能防止恶意节点用诚信买行为掩盖恶意卖行为;而且从信誉值上无法区分初始节点和恶意节点.提出一种新的分布式信任机制,基于交易历史,通过迭代求解,为每个节点计算全局买信誉值和卖信誉值,根据信誉值便能判断节点的善恶.仿真实验对比和性能分析表明,与EigenTrust算法相比,该算法能够迅速降低恶意节点的全局信誉值,抑制合谋攻击,降低恶意交易概率.

抗共谋攻击的视频水印算法

提出了一种基于内容的抗线性共谋攻击的视频水印算法。根据图像的视觉特征以及区域DCT系数的关系,选择水印嵌入区域。利用局部JND(just-noticeable distortion)值,得到一种自适应的基于视觉内容的扩频水印方案。实验结果表明,该水印方案能有效地抵抗第一类和第二类线性共谋攻击,具有较强的顽健性、稳定性和视觉不可见性。