An unified approach on security evaluation against sidechannel attacks on cryptographic algorithms

智能卡等移动的设备正在渗透到我们的日常生活中，以使我们感到舒适。当密码方案在智能卡等计算机上实现时，侧信道攻击是对它们的特别威胁。由于电力是从它们的外部提供的，攻击者可以在它们执行加密操作时观察功耗。在侧信道攻击中，攻击者利用功耗来揭示秘密，因为功耗通常与密钥相关联的操作相关联。为此，我们首先尝试了已知的攻击对策，并研究了边信道攻击的本质。然后，我们利用本质构造有效的对策，适用于移动的设备。(1)We提出了两种针对已知对策的新颖攻击。一种是侧信道攻击， ...更多信息 Oswald对策的二阶微分功率分析，以及M″oller对策的二阶微分功率分析。Oswald提出了一种随机加减链对策，它利用了整数的带符号数字表示和随机化。并通过预计算表给出了对抗措施的脆弱性。我们还提出了两个新的对策，对侧信道攻击。一种是使用椭圆曲线的蒙哥马利形式的对策，另一种是使用宽度w非相邻形式的对策。蒙哥马利提出了椭圆曲线的蒙哥马利形式，以加速椭圆标量乘法。(2)We讨论了一种可能的对“随机二进制签名数字”的攻击，并对这种保护进行了攻击。我们还研究了XRT密码系统，并与传统的离散对数密码系统进行了比较。（3）从侧信道密码分析的角度讨论了Koblitz曲线密码体制的安全性，并针对已知的攻击提出了两种防范措施。侧信道攻击及其对策的研究是未来的研究方向。少

Mobile devices such as smartcards are penetrating in our daily life in order for us to be comfortable. When cryptographic schemes are implemented on computers such as smartcards, side channel attacks are particular menaces to them. Since electric power is provided from the outside of them, the attacker can observe the power consumption while they perform cryptographic operations. In side channel attacks, the attacker utilizes the power consumption for revealing the secret, since the power consumption is usually linked to the operations associated with the secret key.The aim of this research to construct efficient countermeasures against side channel attacks. For this purpose, we first attempt to attack the known countermeasures, and study the essence of side channel attacks. Then, we utilizes the essence for constructing efficient countermeasures which are suitable for the mobile devices.(1)We propose two novel attacks against known countermeasures. One is a side channel attack against … More Oswald's countermeasure, and the other is a second-order differential power analysis against M″oller's countermeasure. Oswald proposed a randomized addition-subtraction chains countermeasure, which utilizes a signed digit representation of an integer together with randomization. And we also show the vulnerability of countermeasures with pre-computation table. We also propose two novel countermeasures against side channel attacks. One is a countermeasure using the Montgomery form of elliptic curves, and the other is a countermeasure using the width-w non-adjacent form. Montgomery proposed the Montgomery form of elliptic curves in order to accelerate the elliptic scalar multiplication.(2)We discuss a possible attack against "Randomized Binary Signed Digits", and give some attack on this protection. We also study the cryptosystem XRT with comparision to conventional discrete-log cryptosystems.(3)Security of Koblitz-curve based cryptosystems is discussed from the view point of sidechannel cryptoanalysis, and proposed two counter measures against known attacks. A future research topic is study on sidechannel attacks and their counter measures. Less