Resistance against side channel attack for RSA cryptosystem

Based on the structure of the side channel attacks （SCAs） to RSA cryptosystem can resist the fault attack and combine with the randomization method for the message and secret exponent, a new implementation scheme of CRT-based （the Chinese remained theorem） RSA is proposed. The proposed scheme can prevent simple power analysis （SPA）, differential power analysis （DPA） and time attack, and is compatible with the existing RSA-CRT cryptosystem as well. In addition, an improvement for resisting fault attack is proposed, which can reduce extra computation time.

Side-Channel Attacks & Data Exfiltration Using Wall Outlet USB Power Adapters

The number and creativity of side channel attacks have increased dramatically in recent years. Of particular interest are attacks leveraging power line communication to 1) gather information on power consumption from the victim and 2) exfiltrate data from compromised machines. Attack strategies of this nature on the greater power grid and building infrastructure levels have been shown to be a serious threat. This project further explores this concept of a novel attack vector by creating a new type of penetration testing tool: an USB power adapter capable of remote monitoring of device power consumption and communicating through powerline communications.

Secure and efficient elliptic curve cryptography resists side-channel attacks

An embedded cryptosystem needs higher reconfiguration capability and security. After analyzing the newly emerging side-channel attacks on elliptic curve cryptosystem （ECC）, an efficient fractional width-w NAF （FWNAF） algorithm is proposed to secure ECC scalar multiplication from these attacks. This algorithm adopts the fractional window method and probabilistic SPA scheme to reconfigure the pre-computed table, and it allows designers to make a dynamic configuration on pre-computed table. And then, it is enhanced to resist SPA, DPA, RPA and ZPA attacks by using the random masking method. Compared with the WBRIP and EBRIP methods, our proposals has the lowest total computation cost and reduce the shake phenomenon due to sharp fluctuation on computation performance.

Adaptive multilevel fuzzy-based authentication framework to mitigate Cache side channel attack in cloud computing

Cloud computing supports multitenancy to satisfy the users’demands for accessing resources and simultaneously it increases revenue for cloud providers.Cloud providers adapt multitenancy by virtualizing the resources,like CPU,network interfaces,peripherals,hard drives and memory using hypervisor to fulfill the demand.In a virtualized environment,many virtual machines(VMs)can run on the same core with the help of the hypervisor by sharing the resources.The VMs running on the same core are the target for the malicious or abnormal attacks like side channel attacks.Among various side channel attacks in cloud computing,cache-based side channel attack is one that leaks private information of the users based on the shared resources.Here,as the shared resource is the cache,a process can utilize the cache usage of another by cache contention.Cache sharing provides a way for the attackers to gain considerable information so that the key used for encryption can be inferred.Discovering this side channel attack is a challenging task.This requires identification of a feature that influences the attack.Even though there are various techniques available in the literature to mitigate such attacks,an effective solution to reduce the cache-based side channel attack is still an issue.Therefore,a novel fuzzy rule-based mechanism is integrated to detect the cache side channel attackers by monitoring the cache data access(CDA).The factor that determines the attack is CDA in a log file created by the framework during authorization.The proposed framework also utilizes certain security properties including ECC and hashing for the privacy preservation and the decision is made with the aid of a fuzzy logic system.

An Effective and Scalable VM Migration Strategy to Mitigate Cross-VM Side-Channel Attacks in Cloud

Co-residency of virtual machines(VMs) of different tenants on the same physical platform would possibly lead to cross-VM side-channel attacks in the cloud. While most of current countermeasures fail for real or immediate deployment due to their requirement for modification of virtualization structure, we adopt dynamic migration, an inherent mechanism of the cloud platform, as a general defense against this kind of threats. To this end, we first set up a unified practical information leakage model which shows the factors affecting side channels and describes the way they influence the damage due to side-channel attacks. Since migration is adopted to limit the time duration of co-residency, we envision this defense as an optimization problem by setting up an Integer Linear Programming(ILP) to calculate optimal migration strategy, which is intractable due to high computational complexity. Therefore, we approximate the ILP with a baseline genetic algorithm, which is further improved for its optimality and scalability. Experimental results show that our migration-based defense can not only provide excellent security guarantees and affordable performance cost in both theoretical simulation and practical cloud environment, but also achieve better optimality and scalability than previous countermeasures.

An Efficient Method against Side-Channel Attacks on ECC

Side-channel attacks （SCA） may exploit leakage information to break cryptosystems. In this paper we present a new SCA resistant Elliptic Curve scalar multiplication algorithm. The proposed algorithm, builds a sequence of bit-strings representing the scalar k, characterized by the fact that all bit-strings are different from zero; this property will ensure a uniform computation behavior for the algorithm, and thus will make it secure against simple power analysis attacks （SPA）. With other randomization techniques, the proposed countermeasures do not penalize the computation time. The proposed scheme is more efficient than MOEller＇s one, its cost being about 5% to 10% smaller than MOEller＇s one.

UTILITY ANALYSIS AND EVALUATION METHOD STUDY OF SIDE CHANNEL INFORMATION

In order to improve the efficiency and success rate of the side channel attack,the utility of side channel information of the attack object must be analyzed and evaluated before the attack implementation.Based on the study of side-channel attack techniques,a method is proposed in this paper to analyze and evaluate the utility of side channel information and the evaluation indexes of comentropy,Signal-to-Noise Ratio(SNR)are introduced.On this basis,the side channel information(power and electromagnetic)of a side channel attack experiment board is analyzed and evaluated,and the Data Encryption Standard(DES)cipher algorithm is attacked with the differential power attack method and differential electromagnetic attack method.The attack results show the effectiveness of the analysis and evaluation method proposed in this paper.

Side-Channel Analysis for Detecting Protocol Tunneling

Protocol tunneling is widely used to add security and/or privacy to Internet applications. Recent research has exposed side channel vulnerabilities that leak information about tunneled protocols. We first discuss the timing side channels that have been found in protocol tunneling tools. We then show how to infer Hidden Markov models (HMMs) of network protocols from timing data and use the HMMs to detect when protocols are active. Unlike previous work, the HMM approach we present requires no a priori knowledge of the protocol. To illustrate the utility of this approach, we detect the use of English or Italian in interactive SSH sessions. For this example application, keystroke-timing data associates inter-packet delays with keystrokes. We first use clustering to extract discrete information from continuous timing data. We use discrete symbols to infer a HMM model, and finally use statistical tests to determine if the observed timing is consistent with the language typing statistics. In our tests, if the correct window size is used, fewer than 2% of data windows are incorrectly identified. Experimental verification shows that on-line detection of language use in interactive encrypted protocol tunnels is reliable. We compare maximum likelihood and statistical hypothesis testing for detecting protocol tunneling. We also discuss how this approach is useful in monitoring mix networks like The Onion Router (Tor).

Analysis on the Parameter Selection Method for FLUSH+RELOAD Based Cache Timing Attack on RSA

FLUSH+RELOAD attack is recently proposed as a new type of Cache timing attacks.There are three essential factors in this attack,which are monitored instructions.threshold and waiting interval.However,existing literature seldom exploit how and why they could affect the system.This paper aims to study the impacts of these three parameters,and the method of how to choose optimal values.The complete rules for choosing the monitored instructions based on necessary and sufficient condition are proposed.How to select the optimal threshold based on Bayesian binary signal detection principal is also proposed.Meanwhile,the time sequence model of monitoring is constructed and the calculation of the optimal waiting interval is specified.Extensive experiments are conducted on RSA implemented with binary square-and-multiply algorithm.The results show that the average success rate of full RSA key recovery is89.67%.

An Optimized Cross Correlation Power Attack of Message Blinding Exponentiation Algorithms

The message blinding method is the most efficient and secure countermeasure against first-order differential power analysis(DPA).Although cross correlation attacks(CCAs) were given for defeating message blinding methods,however searching for correlation points is difficult for noise,misalignment in practical environment.In this paper,we propose an optimized cross correlation power attack for message blinding exponentiation algorithms.The attack method can select the more correlative power points of share one operation in the modular multiplication by comparing variances between correlation coefficients.Further we demonstrate that the attack method is more efficient in experiments with hardware implementation of RSA on a crypto chip card.In addition to the proposed CCA method can recovery all 1024 bits secret key and recognition rate increases to 100%even when the recorded signals are noisy.

Collision-Based Chosen-Message Simple Power Clustering Attack Algorithm

Chosen-message pair Simple Power Analysis (SPA) attacks were proposed by Boer, Yen and Homma, and are attack methods based on searches for collisions of modular multiplication. However, searching for collisions is difficult in real environments. To circumvent this problem, we propose the Simple Power Clustering Attack (SPCA), which can automatically identify the modular multiplication collision. The insignificant effects of collision attacks were validated in an Application Specific Integrated Circuit (ASIC) environment. After treatment with SPCA, the automatic secret key recognition rate increased to 99%.

Invariant of Enhanced AES Algorithm Implementations Against Power Analysis Attacks

The security of Internet of Things(IoT)is a challenging task for researchers due to plethora of IoT networks.Side Channel Attacks(SCA)are one of the major concerns.The prime objective of SCA is to acquire the information by observing the power consumption,electromagnetic(EM)field,timing analysis,and acoustics of the device.Later,the attackers perform statistical functions to recover the key.Advanced Encryption Standard(AES)algorithm has proved to be a good security solution for constrained IoT devices.This paper implements a simulation model which is used to modify theAES algorithm using logicalmasking properties.This invariant of the AES algorithm hides the array of bits during substitution byte transformation of AES.This model is used against SCAand particularly Power Analysis Attacks(PAAs).Simulation model is designed on MATLAB simulator.Results will give better solution by hiding power profiles of the IoT devices against PAAs.In future,the lightweight AES algorithm with false key mechanisms and power reduction techniques such as wave dynamic differential logic(WDDL)will be used to safeguard IoT devices against side channel attacks by using Arduino and field programmable gate array(FPGA).

Timing Attack Analysis on AA_βCryptosystem

Timing attack is an attack on the implementation of a cryptographic primitive. The attack collects leaked secret data via certain implementation techniques either on software or hardware. This paper provides an analysis of a theoretical timing attack on the AAβ algorithm. The attack discussed in this paper gives avenues for secure implementation of AAβ against timing attacks. The simulation of the attack is important to provide invulnerability features for the algorithm in order to be implemented and embedded on applications. At the end of the attack, a method to overcome it will be introduced and it is called AAβ blinding.

基于多源数据聚合的神经网络侧信道攻击

基于深度学习的侧信道攻击需要针对密码算法的每一个密钥字节建模并训练,数据采集和模型训练开销大.针对该问题,提出一种基于多源数据聚合的神经网络侧信道攻击方法.为筛选具有良好泛化效果的密钥字节泄露数据进行数据聚合,以AES-128算法为例,先基于16个密钥字节的泄露数据训练16个单密钥字节模型,分别实现对16个密钥字节的恢复;其次,设计一种打分机制评估各单密钥字节模型的泛化效果,通过得分排序筛选出对各密钥字节恢复效果最好的单密钥字节模型;最后,以筛选模型所对应的各密钥字节泄露数据集构建多源数据聚合模型进行训练,实现密钥恢复.实验测试结果表明,多源数据聚合模型具有良好的泛化效果,有效提高了密钥恢复的准确率和效率,降低了恢复密钥所需的能量迹数量,其在采集能量迹较少的情况下依然具有较好的攻击效果.

面向SIMD指令集的SM4算法比特切片优化

SM4算法是中国自主设计的商用分组密码算法,其加解密计算性能成为影响信息系统数据机密性保障的重要因素之一.现有SM4算法优化主要面向硬件设计和软件查表等方向展开研究,分别存在依赖特定硬件环境、效率低下且易遭受侧信道攻击等问题.比特切片技术通过对输入数据重组实现了并行化高效分组密码处理,可以抵御针对缓存的侧信道攻击.然而现有切片分组密码研究对硬件平台相关性强、处理器架构支持单一,并且并行化处理流水启动较慢,面向小规模数据的加解密操作难以充分发挥单指令多数据(single instruction multiple data,SIMD)等先进指令集的优势.针对上述问题,首先提出了一种跨平台的通用切片分组密码算法模型,支持面向不同的处理器指令字长提供一致化的通用数据切片方法.在此基础上,提出了一种面向SIMD指令集的细粒度切片并行处理SM4优化算法,通过细粒度明文切片重组与线性处理优化有效缩短算法启动时间.实验结果表明,相比通用SM4算法,优化的SM4比特切片算法加密速率最高可达438.0 MBps,加密每字节所需的时钟周期最快高达7.0 CPB(cycle/B),加密性能平均提升80.4%~430.3%.

一种基于模板的RSA-CRT模约减攻击方法

目前针对RSA-CRT的建模类攻击研究较少,本文以模约减操作为研究对象,提出了一种针对RSA-CRT实现的模板攻击方法.该方法的核心是解决了如何由模约减后中间值的汉明重量恢复RSA-CRT私钥的难题.该方法的特点是基于模约减后中间值的汉明重量模型建模,通过采集选择密文模约减的能量迹进行模板匹配获取模约减后中间值的汉明重量,由汉明重量变化值恢复中间值,进一步恢复RSA-CRT算法的私钥.另外,该方法的优点在于理想情况下,基于中间值汉明重量模型建立的模板之间可以共用,且对中间值以多少位大小建模没有限制,可以选择字节大小,64位大小,甚至私钥p相同大小,实际环境中可根据泄露信息情况进行选取.最后,本文选择对中间值的最低字节进行建模,验证了该方法的可行性,并给出了防护建议.

uBlock算法的低延迟一阶门限实现方法

目前已有文献给出了uBlock分组密码算法的侧信道防护方案,但是这些方案不仅延迟较高,难以适用于低延迟高吞吐场景,而且在毛刺探测模型下缺乏可证明安全性.针对这一问题,本文给出了在毛刺探测模型下具有可证明安全性的uBlock算法的低延迟门限实现方案.此外,我们引入了Changing of the Guards技术来避免防护方案在执行过程中需要额外随机数.对于防护方案的安全性,我们用自动化评估工具SILVER验证了S盒的毛刺探测安全性,并用泄露评估技术TVLA(Test Vector Leakage Assessment)验证了防护方案的整个电路的安全性.最后,我们用Design Compiler工具对防护方案的性能消耗情况进行了评估.评估结果显示,与序列化实现方式的uBlock防护方案相比,我们的防护方案的延迟能够减少约95%.

针对ZUC算法硬件实现的相关能量攻击与多粒度时域敏感区域检测

本文通过合理分解模加操作,优化流水线结构,构建ZUC算法硬件实现,并基于FPGA开发板搭建ZUC算法功耗采集平台.构建粗细粒度时域敏感区域的泄漏检测方法,利用移动平均算子,发掘高信噪比风险区域,采用自相关滤波器与峰值检测算子,发掘具有明显重复特征的运算区间,并对泄漏高风险区域进行标定,实现高精度的泄漏风险定位.通过分析ZUC算法的脆弱性,本文提出一种基于选择初始向量IV的CPA攻击方案,对输入的IV信息进行选择,通过固定部分明文的方法有效提高采集信号的信噪比,并采集实际3000条功耗曲线,在算法初始化首轮,成功提取8 bit密钥信息,从而证明该方案的有效性,对ZUC算法的硬件实现进行侧信道防护是必要的.总结ZUC算法侧信道防护方案,对比方案优劣.

处理器时间侧信道攻防技术综述

现代处理器优化机制众多,设计人员在追求性能提升时,往往忽略背后的安全风险。时间侧信道攻击因其影响面广且隐蔽性好已成为最主要的安全威胁之一。随着瞬态执行攻击的出现,时间侧信道攻击的能力被进一步扩展,计算系统的安全基础被动摇。为此,处理器厂商及安全人员提出了大量防御机制。这些机制具有不同的防护能力及性能开销。与此同时,新的瞬态执行漏洞和隐蔽信道也不断被发现,已提出的防御机制被不断突破。围绕处理器时间侧信道攻防技术的博弈日益激烈。本文从基本攻击原理出发,对现有时间侧信道攻击进行了归纳总结,并在此基础上进一步分析了相关防御机制的保护能力和性能瓶颈,从而梳理出时间侧信道攻防技术的发展趋势,为未来软硬件系统开发和安全技术探索提供参考。

x86处理器向量条件访存指令安全脆弱性分析

单指令多数据流(Single Instruction stream,Multiple Data streams,SIMD)是一种利用数据级并行提高处理器性能的技术,旨在利用多个处理器并行执行同一条指令增加数据处理的吞吐量.随着大数据、人工智能等技术的兴起,人们对数据并行化处理的需求不断提高,这使得SIMD技术愈发重要.为了支持SIMD技术,Intel和AMD等x86处理器厂商从1996年开始在其处理器中陆续引入了MMX(MultiMedia Extensions)、SSE(Streaming SIMD Extensions)、AVX(Advanced Vector eXtensions)等SIMD指令集扩展.通过调用SIMD指令,程序员能够无需理解SIMD技术的硬件层实现细节就方便地使用它的功能.然而,随着熔断、幽灵等处理器硬件漏洞的发现,人们逐渐认识到并行优化技术是一柄双刃剑,它在提高性能的同时也能带来安全风险.本文聚焦于x86 SIMD指令集扩展中的VMASKMOV指令,对它的安全脆弱性进行了分析.本文的主要贡献如下:(1)利用时间戳计数器等技术对VMASKMOV指令进行了微架构逆向工程,首次发现VMASKMOV指令与内存页管理和CPU Fill Buffer等安全风险的相关性;(2)披露了一个新的处理器漏洞EvilMask,它广泛存在于Intel和AMD处理器上,并提出了3个EvilMask攻击原语:VMASKMOVL+Time(MAP)、VMASKMOVS+Time(XD)和VMASKMOVL+MDS,可用于实施去地址空间布局随机化攻击和进程数据窃取攻击;(3)给出了2个EvilMask概念验证示例(Proof-of-Concept,PoC)验证了EvilMask对真实世界的信息安全危害;(4)讨论了针对EvilMask的防御方案,指出最根本的解决方法是在硬件层面上重新实现VMASKMOV指令,并给出了初步的实现方案.