Itaru Nakamura, Natsuki Sakamoto, Yukiko Ida, Ryutaro Imai, Kotaro Aoki, Rina Ando, Tetsuo Yamaguchi, Hajime Matsumura, Tetsuya Matsumoto Department of Infection Control and Prevention, Tokyo Medical University Hospital, Tokyo, Japan; Department of Plastic and Reconstructive Surgery, Tokyo Medical University, Tokyo, Japan; Department of Microbiology and Infectious Diseases, Toho University Scho...

Seeking an answer to the question once posed by Tadao Satō: “Is there a Japanese film theory?,” author of article makes critical review publications which appeared in first decades 20th century. Loska draws attention both influence Western philosophical trends (neo-Kantism) and importance native aesthetic inspirations (the Kyoto school). When discussing theoretical concepts, focuses on issues r...

We develop several tools to derive linear independent multivariate equations from algebraic S-boxes. By applying them to maximally nonlinear power functions with the inverse exponents, Gold exponents, or Kasami exponents, we estimate their resistance against algebraic attacks. As a result, we show that S-boxes with Gold exponents have very weak resistance and S-boxes with Kasami exponents have ...

In this paper we determined explicitly the multiplicative inverses of the Dobbertin and Welch APN exponents in Z2n−1, and we described the binary weights of the inverses of the Gold and Kasami exponents. We studied the function Invd (n), which for a fixed positive integer d maps integers n ≥ 1 to the least positive residue of the inverse of d modulo 2n − 1, if it exists. In particular, we showe...

Algebraic attacks have received a lot of attention in studying security of symmetric ciphers. The function used in a symmetric cipher should have high algebraic immunity (AI) to resist algebraic attacks. In this paper we are interested in finding AI of Boolean power functions. We give an upper bound on the AI of any Boolean power function and a formula to find its corresponding low degree multi...

The question if there exist nonnormal bent functions was an open question for several years. A Boolean function in n variables is called normal if there exists an affine subspace of dimension n/2 on which the function is constant. In this paper we give the first nonnormal bent function and even an example for a nonweakly normal bent function. These examples belong to a class of bent functions f...