文章以网络攻击与防御课程为例,结合传统的教学方法存在的不足之处,提出基于OBE理念的教学设计,介绍运用ADDIE模型从分析确定教学目标、设计教学内容、开发教学材料、选择实施策略和进行课程考核评估五个方面进行教学设计与实践.实践证明,采用该模型不仅给教师在备课、授课过程环节给予指导,同时也保证学生学有所获,促进教学质量的提高,也为其他课程的改革提供新的思路和方法.

A method for an online power analysis attack platform against SM3-based HMAC was proposed in the paper. The method adopts a front-end and back-end approach. The front-end implements functions such as uploading power traces, displaying power traces, and inputting power analysis attack parameters. The back-end completes correlation power analysis attack based on the power traces and attack parameters uploaded by the front-end, and returns the attack results to the front-end for display. This design fully utilizes the powerful computing capabilities of the backend server, while also supporting the simultaneous use of multiple detecting users. It has broad application prospects and promotion value.

轻量级分组密码算法PRESENT采用了 SPN网络结构,具有实现面积小、功耗低等特点,因此广泛使用于资源受限的环境中.针对PRESENT算法,设计多字节故障模型,在PRESENT算法的第30、29轮的任意位置分别进行随机故障注入,注入的字节数不固定.利用PRESNET算法的故障传播路径,构建输出差分和可能输入值之间的关系,通过提出的并行S盒分析方法得到正确输入,进而得到正确的轮子密钥.最后通过分析密钥编排方案,只需要两轮正确的轮子密钥即可推导出初始的80 bits主密钥.实验结果表明,与现有的针对PRESENT算法的故障攻击相比,利用提出的故障模型,可以将攻击复杂度由231降低到218,并且轮密钥攻击平均时长由20000 ms降低到1000 ms.与此同时,提出的方法将单字节、固定位置故障模型改进为多字节、任意位置的故障模型,更加符合实际的攻击情况,降低了对故障注入设备的要求,提高方法的实用性.

目前针对GOST算法提出的差分故障攻击方法均对故障模型做了假设限定,其要求在特定的时机或位置引入故障.但在实际攻击中,攻击者难以精确控制故障的发生,攻击的普适性较差.此外,国内外已有的攻击实验均为仿真数据,回避了真实攻击中会遇到的错误密文筛选问题.基于此,提出一种基于随机故障注入的GOST差分故障攻击方法.该方法将随机故障注入区间扩大至GOST算法的最后八轮,在注入完成后只需简单筛选错误密文样本,即可利用密钥筛选方法依次恢复出最后八轮子密钥,最终达到恢复算法主密钥的目的.并对无防护GOST智能卡进行了电源故障注入攻击实验,实验结果表明,该方法不仅能在真实实验环境中成功恢复出算法的主密钥,而且扩大了故障诱导的范围,降低了攻击的难度,提高了攻击的灵活性和实用性.

传统侧信道攻击利用加密设备泄露的物理信息来获取密钥,由于其需要大量人为干预,越来越多研究将机器学习算法运用到侧信道攻击中,其中神经网络攻击效果最好,而多层感知器又是神经网络的基础,其中超参数在很大程度上影响最终训练与攻击结果.为实现超参数自动寻优,将贝叶斯寻优的方法应用在侧信道多层感知器攻击中,并提出对离散值的处理方法,发展出能够结合超参数经验的侧信道多层感知器超参数寻优方法.实验对比了人工寻优与贝叶斯寻优两种算法用于侧信道多层感知器攻击中的效率,验证了多层感知器与侧信道攻击相结合及贝叶斯寻优的可行性和高效性.

Aiming at the efficiency of traditional template attacks in actual attacks, this paper focuses on the ResN et network model with excellent feature extraction capabilities in the field of image recognition, and proposes a template attack method based on the ResN et network model. In order to adapt the neural network to the characteristics of the side channel data, the network model structure was adjusted appropriately. In the experiment, the traditional multivariate Gaussian distribution and the ResNet-based convolutional neural network model were used to establish templates. The final experimental results show that the success rate of template attacks based on the ResNet model is 94.5%, which is 9.4% higher than the traditional template attacks.

目前针对SM4密码算法的侧信道攻击研究主要是故障分析攻击和相关性能量分析攻击,为了探索模板攻击针对SM4密码算法分析攻击应用问题,提出了针对SM4密码算法的模板攻击方法,模板构建时,选择SM4密码算法的S盒输出作为能量分析攻击点,汉明重量作为能量分析模型,构建关于S盒输出的模板,模板匹配时,选择多条曲线的联合概率进行匹配,概率最大值对应的密钥即为攻击出的正确密钥.针对SM4密码算法智能卡实测实验,验证了该攻击方法的有效性.该攻击方法不仅可以应用到针对SM4密码算法其他攻击点的模板攻击,而且对其他分组密码算法的模板攻击具有借鉴意义.

传统安全总线的安全机制一般采用固定存储密钥和国际密码算法,这种方式存在不可控因素和密钥被侵入攻击的安全风险,针对传统总线传输存在的风险问题,提出一种基于国密算法和物理不克隆函数的安全并行总线,该总线设计了一种环形振荡器物理不克隆函数和密钥生成机制,将物理不克隆函数结合随机数发生器由SM3密码算法生成密钥,采用国密SM4密码算法对总线上传输的数据进行加密,加密时为了安全因素采用随机数对明文进行填充,保证了总线数据传输的安全性.通过该安全机制实现的总线,能有效抵御侵入式分析,抵抗重放攻击,解决密钥易被破解问题,保证数据安全性和机密性.最后搭建了并行总线加密仿真平台,验证了该方案的可行性.

密码设备在进行加解密时会产生大量的物理信息,如电磁、能耗、热量等.攻击者利用这些物理信息对密码设备进行侧信道攻击,窃取密码设备的密钥.就传统的椭圆曲线加密算法简单能量分析攻击而言,攻击者通过人工识别倍点计算能耗数据中的相似模块,从而恢复出密钥.这种攻击方式导致攻击效率低,准确率不高.本文基于时间序列的模体发现提出了SPAMD算法,该算法实现了倍点计算的能耗数据中相似模块的自动识别,完成了攻击方式从人工识别到自动识别的转换.实验结果表明SPAMD攻击在效率和准确率上有了显著的提升.

基于巴特沃斯滤波算法在现场可编程逻辑门阵列(FPGA)侧信道攻击中的使用,主要利用巴特沃斯滤波算法对功耗曲线进行预处理,然后用神经网络模型代替传统模板攻击的统计模型对功耗曲线进行侧信道攻击.该算法对模板攻击,随机方法,深层感知器以及深层卷积神经网络的功耗曲线预处理具有普适性,在实验部分针对DPA CONTEST V2数据进行了4种侧信道方法的分析,实验数据表明该方法提高了可攻击的信噪比,同时提高了侧信道攻击的成功率.

Security of cyber-physical systems against cyber attacks is an important yet challenging problem. Cyber-physical systems are prone to information leakage from the physical domain. The analog emissions, such as magnetic and power, can turn into side channel revealing valuable data, even the crypto key of the system. Template attack is a popular type of side-channel analysis using machine learning technology. Malicious attackers can use template attack to profile the analog emission, then recover the secret key of the system. But conventional template attack requires that the adversary has access to an identical experiment device that he can program to his choice. This study proposes a novel side-channel analysis for physical-domain security in cyber-physical systems. Our contributions are the following three points: (1) Major peak region method for finding points of interests correctly is proposed. (2) A method for establishing templates on the basis of those points of interest still without requiring knowledge of the key is proposed. Several techniques are proposed to improve the quality of the templates as well. (3) A method for choosing attacking traces is proposed to significantly improve the attacking efficiency. Our experiments on three devices show that the proposed method is significantly more effective than conventional template attack. By doing so, we will highlight the importance of performing similar analysis during design time to secure the cyber-physical system.

针对SM4密码算法,提出一种新型的约减轮故障攻击方法,故障注入于加密算法的前4轮中,使加密算法的后续迭代轮数减少,对故障数据进行筛选和分析,理论上由4个错误密文就可以恢复128 bit的初始密钥,从而完成攻击.方法 对比现有针对SM4的差分故障攻击方法有很大的简化,提高了攻击效率.利用攻击方法对无防护SM4算法的智能卡进行了约减轮故障注入攻击,实验结果表明攻击方法行之有效,也可以扩展到其他分组密码.

A broadband high-gain periodic endfire antenna is presented in this article. The broadband is achieved by using a planar out-of-phase power divider with ultra-wideband performance and periodic dipole elements. The device uses two substrates with a common ground plane. A coupling between two microstrip lines on the top and bottom substrate layers through a slot in the common ground plane, and a transition from two microstrip lines to a parallel stripline are used to achieve an ultra-wideband operation. The gain enhancement is achieved by loading with an I-shape resonator (ISR) structure in the endfire direction. The effect of the I-shape unit cell structure on the gain enhancement is investigated. Both the ISR-loaded antenna and unloaded one are fabricated to verify the predictions. The measurements show that ISR-loaded antenna presents gain of about 7 dB-10 dB in the whole working band (3GHz-11GHz), which is about 2 dB-3.5 dB more than the unloaded one. The proposed antenna can be using in wireless communication systems for its advantages of broad bandwidth and high-gain.

A novel wideband periodic endfire antenna is presented. Broad bandwidth is realized by using a parallel strip line (PSL) feed and dipole elements. A coupling between two microstrip lines on the top and bottom substrate layers through a slot in the common ground plane, and a transition from two microstrip lines to a parallel stripline are used to achieve an wideband operation. The regular dipole shape is modified to a quasi-rhombus shape by adding two triangular patches. Using two dipoles helps maintain stable radiation patterns close to their resonance frequencies. A modified array configuration is proposed to further enhance the antenna radiation characteristics and usable bandwidth. The proposed antenna provides endfire radiation patterns with high gain, high front-to-back (F-to-B) ratio,wide beamwidth in a wide bandwidth of the 130%

A gain enhancement wideband Quasi-Yagi elliptic dipole antenna is presented in this letter. The gain enhancement is achieved by loading with spliting-ring resonator (SRR) structures in the endfire direction while broad bandwidth is realized by using a microstrip-to-coplanar balun and elliptic dipole elements. The measurement results show the SRRs-loaded antenna presents around 5GHz-8GHz dB gain in the whole working band (5GHz-11GHz), which is around 2 dB more than the unloaded one. This antenna can be used in wireless communication systems for its advantages of broad bandwidth, endfire radiation and high gain.

This paper presents the design and implementation of a novel wide bandwidth end fire antenna with log-periodic directors. The feeding structure of the proposed antenna includes a balun which is formed using a pair of microstrip to slot line transitions. The proposed antenna has three resonant frequencies in the operating frequency band. Both simulation and measurement results show that the operating frequency band of the antenna for S11 <; -10 dB covers the wide bandwidth (5GHz-10GHz), and the relative bandwidth is 67%. Far field measurements in azimuth plane and elevation plane show that the radiation patterns are stable and end fire within the operating band at frequencies of 5GHz, 7GHz, 8GHz, 10GHz. The proposed antenna radiates a well defined end fire beam, with a front-to-back ratio > 20dB and cross polarization level below -29dB. The dimension of the proposed antenna is 26mm × 27mm. Good return loss and radiation pattern characteristics are obtained and measured results are presented to validated the usefulness of the proposed antenna structure for wide bandwidth end fire applications.

本文提出了针对SM4选择明文能量分析的选择明文算法.选择明文时,先选择轮输入中部分字节为随机数.通过约束条件,再计算轮输入的剩余字节.最后根据SM4密码算法的轮函数,反推出对应的明文.该明文即是满足针对SM4选择明文能量分析所述约束条件的明文.该选择明文算法的时间复杂度为常数阶,不需要穷举搜索明文.相比通过穷举明文的方式,该算法降低了时间复杂度,解决了数据搜索空间的问题,提高了明文的选择效率.本文提出的算法解决了Wang Min于2015年提出的针对SM4的选择明文能量分析的问题之一,即如何高效率的选择满足约束条件的明文,从而提高分析效率.目前国内外尚未有公开发表的文献,所以实际分析时,实施者可以通过穷举明文且满足约束条件的方式来获取合适的明文,采集能量曲线,实施针对SM4的选择明文能量分析,但这种选择明文方式存在数据搜索空间大、时间复杂度大等问题,导致该方法实际分析时不可行.应用本文提出的算法,通过对SM4选择明文能量分析实验进行了验证,实验验证了本方法是行之有效的.

This paper proposed a novel 100% bandwidth end-fire log-periodic monopole antenna array that can cover the wide bandwidth from 6GHz to 18GHz. The proposed log-periodic monopole antenna array removed the complicated feeding network in the design of the conventional log-periodic monopole antenna array, and corrected the errors discussion in design of the log-periodic monopole antenna array that is not formed the cross-inverting feeding on the ground plane. The proposed log-periodic monopole antenna uses the slot line as feed circuit to achieve the cross feed on the ground plane while keeping the symmetry of the antenna structure. The proposed antenna can keep good end-fire radiation over the whole operational frequency (6GHz-18GHz). The proposed log-periodic monopole antenna array has a compact size(45mm× 30mm × 12mm).

The known-key establishment template and others full control of experimental equipment preconditions are required to implement the traditional template attack.The preconditions restrict the application scenario of template attack.The template attack is only applied to the device that the key input can be controlled.In order to resolve the restrictive preconditions,a novel method of template attack based on clustering was proposed.The clustering EM algorithm was modified according to the characteristics of information leakage model in the method.The modified clustering methods accurately fitted the leaked information probability model in the case of unknown key,the location of information leakage could be determined.Then the attack established the templates in the location,and implemented template matching.The proposed method eliminates the dependence of traditional template attacks on per-conditions and expand the application scenario of template attack.