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

为了让我们感到舒适，智能卡等移动设备正在渗透到我们的日常生活中。当加密方案在诸如智能卡之类的计算机上实施时，侧通道攻击对它们是特别的威胁。由于电力是从它们的外部提供的，所以攻击者在执行加密操作时可以观察到功耗。在侧信道攻击中，攻击者利用功率消耗来泄露秘密，因为功率消耗通常与与密钥相关的操作相关联，该研究的目的是构建有效的对抗侧信道攻击的对策。为此，我们首先尝试对已有的攻击对策进行攻击，并研究侧向通道攻击的本质。然后，我们利用这一本质来构造适用于移动设备的高效对策。(1)针对已有对策提出了两种新的攻击方法。一种是针对…的旁路攻击更多的是奥斯瓦尔德的对策，另一种是针对莫勒的对策的二阶微分功率分析。Oswald提出了一种随机化加减链对策，它利用了整数的带符号数字表示和随机化。并以预计算表的形式展示了对策的脆弱性。我们还提出了两种新的抗侧信道攻击的对策。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。为了加速椭圆标量乘法运算，Montgomery提出了椭圆曲线的Montgomery形式。(2)讨论了针对随机二进制有符号数字的一种可能的攻击，并给出了对这种保护的一些攻击。并与传统的离散对数密码体制进行了比较。(3)从边通道密码分析的角度讨论了基于Koblitz曲线的密码体制的安全性，并提出了两种针对已知攻击的对策。侧向通道攻击及其对抗技术的研究是今后的研究方向。较少

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