On the study of physical cryptanalysis

• Main Author: 楊舜民
• Other Authors: 顏嵩銘
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/01330540871944623383

碩士 === 國立中央大學 === 資訊工程研究所 === 89 === Nowadays, some popular and small electronic devices, e.g., smart IC cards, are developed in order to provide possible solutions for data security, such as data processing and storage. However, these devices operate frequently in public environments and may suffer to leak secret information. In this thesis, physical cryptanalysis will be examined with great details. Physical cryptanalysis analyze careless implements of cryptosystems and open a brand new direction of cryptanalysis during the past few years. In this thesis, we focus especially on the fault-based attack and timing attack. In Chapter 4, new fault-based attacks on IDEA and RC5 (and also RC6) ciphers are considered. These attacks are conducted upon either modular addition or modular multiplication. Moreover, these two modular operations are used frequently in many cryptosystems, so their security should be considered extensively. Analysis shows that the considered cryptanalysis in this thesis is reasonable. Division chain algorithm was originally developed for improving exponentiation computation. In Chapter 5, the concept of randomized division chain is proposed to counteract the possible timing cryptanalysis when performing an exponentiation computation. Hybrid attacks, i.e., a novel combination of more than one physical cryptanalysis at the same time, are believed to be much powerful than any single physical cryptanalysis. In Chapter 6, possible guidelines, although not exhaustive, to prevent hybrid attacks are considered.