| dc.description.abstract | Nowadays, digital information grows extremely in our daily life, and the requirement of tamper-resistant device that endowed with executing the procedures of cryptosystems or storing the ersonal
secret information increases correspondingly. The smart cards are becoming the representative of tamper-resistant device. However, when these cryptosystems are operated in the open environment, no one can ensure the security of information even information is protected by cryptosystems. Physical cryptanalysis is a modern and increasingly potent threat to the security of information held on smart cards. By measuring physical features such as power consumption, time spending or electromagnetic emission, the attackers can infer secret information from smart cards with naive implementations of cryptosystems.
The Advanced Encryption Standard (AES) is the next generation standard block cipher selected by NIST to replace DES in 2000. AES will become the most widespread block cipher standard. Power
analysis attack is the most useful cryptanalysis at present, and it is also practicable on the AES. In this thesis, the power analysis against AES will be discussed.
The simple power analysis (SPA) is easy to realize in real world. In order to defend the AES against SPA, the weakness of existence SPA-resistant countermeasures are analyzed, and an
improvement is proposed. Second, the DPA-resistant algorithms of AES suffer from high-order differential power analysis (HODPA). To
this end, possible countermeasure is also discussed.
The balanced Hamming weight scheme is one of the effective ways to prevent from power analysis attack. We found that even involving the balanced Hamming weight to protect AES, it may not secure enough under some careless implementations. The weaknesses of balanced Hamming weight scheme will be analyzed and the procedure of the proposed flipping DPA attack is described to derive the secret key of AES.
In this thesis, the experiments will be shown at the end of each proposed method to confirm our contentions. Some experiments, especially the SPA-based attack, the power trace will be pre-process before analyzing. At the end of this thesis, the
pre-process technique will be described. | en_US |