Improvement on bit diffusion analysis of Pi-Cipher

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bölümü, Türkiye

Tezin Onay Tarihi: 2016

Öğrenci: BEYZA BOZDEMİR

Danışman: ALİ DOĞANAKSOY

Özet:

Pi -Cipher, a sponge-based algorithm designed by Gligoroski et al., is a second round algorithm of the CAESAR competition. The designers of Pi-Cipher analyzed the bit diffusion of the parts, star operation and 1 round pi -function for all variants of Pi -Cipher. They showed the results with graphics; yet, they did not give any conclusion about these results. We improve this analysis by applying Strict Avalanche Criterion (SAC) Test in the package of Cryptographic Randomness Testing designed by Doğanaksoy et al. to star operation for all w values and reduced round versions of pi-function for 16-Cipher. We obtain that star operation for all word sizes fails SAC Test whereas reduced round versions of pi-function pass the test.