【作者】 刘鸣；

【导师】 陈弘毅；

【作者基本信息】 清华大学 ， 电子科学与技术， 2005， 硕士

【摘要】 密码芯片在信息安全中具有重要的基础性作用。密码芯片的安全性是信息系统安全的一个必要条件。密码芯片的不适当的实现可能会通过功耗、时间、电磁辐射等所谓“边缘信道”泄漏内部的关键信息,导致密码芯片自身的不安全。功耗分析就是通过获取、分析密码芯片的功耗曲线推导密钥、破解密码的一类方法。该方法的出现给密码芯片的安全带来了严重的挑战。为了研究密码芯片的功耗分析及抗功耗方法,在现有芯片设计流程和软件工具上,论文构造了功耗分析模拟研究平台。该平台是通过软件模拟的方式获得芯片的功耗曲线,在一定程度上可以避免ASIC生产所带来的风险,并且便于学术研究。在该平台上,论文针对一个ASIC方式实现的DES运算核,研究并实现了基于汉明差的差分功耗分析方法,并给出了分析所需明文数量的预测方法。实验结果证明了汉明差与功耗相关性的存在,此类差分功耗分析方法可以对具有特定结构的分组加密算法芯片进行有效的分析。独立电源模块是一种利用电容储、放电功能而实现的通用型抗功耗分析方法。该模块具有结构简单,附加功耗低等优点。论文对这种方法的ASIC实现进行了可行性研究。针对一个具有40000个晶体管的DES算法芯片,论文提出了两种独立电源模块设计方案。实验结果表明:当电容等于100pf,总面积约75*150um2时,独立电源模块可以使得芯片正常工作,且可以抵抗差分功耗分析。因此,独立电源模块具有集成在芯片内的可能性。更多还原

【Abstract】 Cryptographic chip plays an important fundamental role in InformationSecurity. The security of a cryptographic chip is one of necessary conditionsfor the Security of Information System. The improper implementation of acryptographic chip may leak key information of the chip through so called“side channels” as power, timing, and electromagnetic emanations, whichmake cryptographic chip insecure. The Power Analysis is a type of method toinfer secret key by analyzing power curves of a cryptographic chip. Thismethod brings serious challenge for the security of Cryptographic Chip.To study the method of power analysis and anti-power analysis oncryptographic chip, based on current chip design flow and soft tools, asimulation platform for research was constructed in this thesis. This platformacquires power curves of a chip by method of soft simulation through whichcan avoid the risk of ASIC production and is convenient for academicresearch.Based on the platform, thesis studied and carried out a type ofDifferential Power Analysis based on hamming difference, which aimed at analgorithm core of DES by ASIC, and provided a method to forecast thenumber of messages needed for power analysis. The experiment results provethe existence of correlation between hamming difference and power, and theeffectiveness of this type of method for a block cipher chip with specialconstruction.Detached Power Module is a type of common method against PowerAnalysis by using capacitors that can charge and discharge. This module hasmerits as simple structure, low additional power consumption and so on.Aiming at a DES module that has about 40000 transistors, thesis put forwardtwo types of Detached Power Module and simulated them. Experiment resultsindicate that a cryptographic chip combined with this module can workproperly and also can resist differential power analysis when the capacitorsare 100pf of which area is about 75*150um2. Therefore, the Detached PowerModule has possibility to be integrated into a chip.更多还原