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The Cryptographic Mersenne Twister*1

Japanese Version


What is CryptMT?

CryptMT is a stream cipher developed by Makoto Matsumoto (Hiroshima univ.), Takuji Nishimura (Yamagata univ.), Mariko Hagita, (Ochanomizu univ.), and Mutsuo Saito (Hiroshima univ.) in 2005. The latest version is CryptMT ver. 3.

CryptMT is a stream cipher which is a combination of Linear Feedback Shift Register (LFSR) like Mersenne Twister and non-linear filter based on multiplication. The period and high dimension of equidistribution as a stream cipher are theoretically assured. Moreover, it uses a booter to generate shorter sequence efficiently.

CryptMT ver. 3 uses a variant of SFMT as its LFSR, and its multiplicative filter and booter are designed to use SIMD operations efficiently. The period of CryptMT ver. 3 is non-zero multiple of 219937-1, and the dimension of equidistribution of 8-bit output sequence is at least 1241.

Papers, source files, and slides

*1 This work is supported in part by JSPS Core-to-Core Program No. 18005: "New Developments of Arithmetic Geometry, Motive, Galois Theory, and Their Practical Applications."
This work is also partially supported by JSPS Grant-in-Aid for Scientific Research No. 16204002, No. 18654021.No, 18740044, and No. 19204002.