AES是廣泛被應用的區塊加密機制，然而當AES被實作在一般未受保護的智慧卡(Smart card)時，會因為智慧卡的能量消耗，遭受差分能量分析攻擊(DPA)。針對AES，各種防禦DPA方法以及更高階的DPA攻擊持續被研究。許多研究是結合兩種以上的防禦方法，其中遮罩（Masking）防禦方法常被建議使用。本文之研究目的是探討目前AES的遮罩防禦法之瓶頸，並且加以改善。除此之外，本研究實作DPA攻擊AES的線性與非線性運算，比較兩者的優缺點。並且實作以2次差分能量分析(2nd-order DPA)來攻擊在8051單晶片上具有單一遮罩的AES。

AES is a popular block cipher. However, when AES is implemented on smart card, it is vulnerable to DPA (Differential Power Analysis) attacks. It is because the power consumption of the smart card leaks the information of the intermediate results of AES. Various countermeasures for AES against DPA had been suggested and some stronger DPA attacks also had been proposed. Many studies suggest composing several different countermeasures to defend DPA attacks. One countermeasure often used is Boolean masking. Our study dedicates to improving the Boolean masking of AES. This article also compares the experiment results of DPA on the linear and non-linear operations in AES, and presents the experimental results of 2nd-order DPA on single mask AES implemented on 8051.

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