独立成分分析在电磁攻击中的应用

电磁泄漏曲线的对齐与有效点的选取是信息安全的重要研究方向.针对曲线过偏移的问题, 提出了一种新的曲线对齐方法——双峰式相关对齐法.在有效抑制曲线过偏移的同时, 实现了曲线的精确对齐通过独立成分分析(Independent Component Analysis, ICA)方法实现了有效点的选取.通过对电磁泄露曲线求得未知的源信号, 由源信号作为特征点进行分类分析.分别采用ICA、主成分分析(Principal Components Analysis, PCA)、PCA-ICA、ICA-PCA四种方法对数据进行了降维处理.通过支持向量机(Support Vector Machine, SVM)对降维后的数据进行分类对比, 最终得出:在10~100维范围内, PCA-ICA的分类效果最佳, ICA其次, 而ICA-PCA的效果最差; 在100~900维的范围内, PCA与ICA-PCA分类效果随着维度的增加几乎呈直线趋势增加.     

差分功率分析攻击中的信号对齐方法研究

针对差分功耗分析(DPA)攻击的原理及特点,分析了未对齐信号对DPA攻击的影响.论述了现在已知的对未对齐信号的频域和模式识别处理方法,分别分析了它们的原理及优缺点,提出了在时域内对未对齐信号采用分段处理进行对齐的方法.通过实验验证了该方法的正确性及有效性,该方法能够有效的处理未对称信号,提高DPA攻击的效率,减少DPA攻击的样本量.     

基于数据预处理的侧信道分析优化方法

电磁侧信道信息具有数据庞杂无序,信噪比低的特征,对侧信道分析的结果存在较大影响。针对电磁侧信道数据的特性,该文提出一种最小相关差值的对齐方法,通过参考信号的自相关函数与待对齐信号的互相关函数之间的相似度来估计延时差值。同时,提出一种K奇异值分解(KSVD)字典学习的降噪方法,交替迭代进行稀疏编码和字典更新来滤除高频噪声。为了验证数据预处理方法对侧信道分析结果的优化效果,设计并搭建了电磁侧信道测评系统,并基于实际芯片进行了近场电磁侧信道信息采集与分析。该文使用所提预处理方法对电磁数据进行对齐与降噪,通过t-test泄露评估与相关性电磁分析,对比最大相关系数对齐与小波降噪方法,能够将侧信道攻击的效率分别提高29.91%和55.23%。     

基于高级加密标准的远场电磁旁路攻击

电磁旁路攻击是旁路攻击中的一种有效方法，为了克服传统的电磁旁路攻击必须近距离获取电磁信息的局限性，针对没有电磁防护的密码设备提出一种基于相关性分析的远场攻击方法.使用微控制器运行高级加密标准算法，使用天线在远场探测电磁信号，先对采集的电磁信号均值和滤波以减少噪声的影响，再使用相关性分析方法进行旁路攻击，在天线距离微控制器10 m处成功破解出完整的密钥.同时也对远场电磁旁路攻击中的频率和样本量做了深入研究，带有密钥信息的电磁旁路主要集中在一段频率范围内，而且随着样本量的增加密钥信息越明显，以此为基础结合密码芯片产生密钥信息泄露的机理，提出了改进的电磁旁路攻击方法.     

基于能耗旁路泄露的密码芯片模板攻击算法研究

为解决模板攻击对先验知识要求较为苛刻的问题,基于聚类的半监督式模板攻击方法,研究了能耗泄露曲线特征点的选择,提出了基于皮尔逊相关系数和主成分分析(Principal Component Analysis,PCA)方法对旁路泄露进行特征提取的方法.在聚类过程中,通过少量的有标号的信息来辅助并引导聚类过程对无标号数据的聚类处理,放宽了模板攻击的假设条件.以轻量级分组密码(Light Encryption Device,LED)算法旁路泄露为例,通过实验研究了特征选取等因素对密钥恢复的影响,并分析了能量迹中的数据依赖性.研究结果表明:与常规半监督式模板攻击方法相比,所采用的特征提取方法可以有效降低异常数据和噪声的干扰,提高先验信息的利用率及密钥恢复成功率.     

针对基于SM3的HMAC的能量分析攻击方法

现有基于SM3的HMAC的能量攻击方法,仅适用于同时存在汉明重量和汉明距离信息泄露的攻击对象,如果被攻击对象存在单一模型的信息泄露,则这些方法均不适用。针对该局限性,提出了一种针对SM3的HMAC的能量分析新型攻击方法,该新型攻击方法每次攻击时选择不同的攻击目标和其相关的中间变量,根据该中间变量的汉明距离模型或者汉明重量模型实施能量分析攻击,经过对SM3密码算法的前4轮多次实施能量分析攻击,将攻击出的所有结果联立方程组,对该方程组求解,即可推出最终的攻击目标。通过实验验证了该攻击方法的有效性。由于所提方法不仅可以对同时存在汉明重量和汉明距离信息泄露的对象进行攻击,而且还可以对仅存在单一信息泄露模型的对象进行攻击,所以该方法应用的攻击对象比现有的攻击方法应用更广。     

基于模板和KNN算法的能量分析攻击对比研究

能量分析攻击至今仍是针对密码芯片最具威胁的攻击方法之一,针对传统的模板分析攻击和KNN算法的攻击进行对比研究,对比模板攻击和机器学习中的KNN优缺点。首先对皮尔逊相关系数、互信息和最大信息系数、距离相关系数3种降维方法进行了研究;然后对比了相同数量功耗曲线下,特征点数量对两种能量分析的成功率等性能的影响;同时研究了不同降维技术在相同功耗曲线数量和不同功耗曲线数量时对两种能量分析攻击的影响。结果表明,模板攻击在运行速度、占用内存方面优于KNN算法攻击,而在攻击成功率和鲁棒性方面,KNN算法攻击具有更好的表现。     

一种新的ISAR距离对齐算法

距离对齐是逆合成孔径雷达(ISAR)成像处理中的或对齐精度不够高,或运算效率过低,无法满足ISAR实时成像的要求.由于距离对齐算法本质上是一种优化方法,基于优化原理,将启发式方法与搜索法相结合,提出了一种新的距离对齐算法.该算法结合使用频域法和累积互相关法,具体分两步实现:首先利用频域法进行粗对齐,然后将第一步得到的结果作为启发式信息进行累积互相关,大大减小了其搜索范围,得到了精确的距离对齐效果.通过将新算法与其他算法的运算量进行分析比较,结果表明该算法运算效率较高.而对实测数据的成像处理结果证明该算法具有良好的对齐精度.这说明新算法在效率和性能上达到了良好的平衡,适合于ISAR实时成像.     

Jetson Nano神经网络物理电磁泄漏安全研究

如果采用旁路攻击方法对神经网络结构、框架进行攻击,恢复出结构、权重等信息,会产生敏感信息的泄漏,因此,需要警惕神经网络计算设备在旁路攻击领域产生敏感信息泄露的潜在风险。本文基于Jetson Nano平台,针对神经网络及神经网络框架推理时产生的旁路电磁泄漏信号进行采集,设计了基于深度学习方法的旁路攻击算法,对旁路进行分析研究,并对两个维度的安全进行评估。研究表明,良好的网络转换策略能够提升网络分类识别准确率5%~12%。两种评估任务中,针对同一框架下不同结构的典型神经网络推理时,电磁泄漏的分类准确率达到97.21%;针对不同神经网络框架下同一种网络推理时,电磁泄漏的分类准确率达到100%。说明旁路电磁攻击方法对此类嵌入式图像处理器(GPU)计算平台中的深度学习算法隐私产生了威胁。     

PDA上ECC电磁分析神经网络分类方法

电磁分析攻击是对PDA等移动终端设备的椭圆曲线密码系统进行攻击的有效手段.简单电磁分析攻击中的信号分类是一个难点问题.文章针对椭圆曲线密码系统中的标量乘法运算时发射的电磁信号,运用人工神经网络技术进行分类判别,从而获取标量乘法中的秘密参量.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.