The Cryptographic Mersenne Twister^*1

News

• We released CryptMT3 C++ source files. (2013/5/31)
• CryptMT ver. 3 is not selected for eSTREAM Portfolio. The reason is not because of the defect of CryptMT. See The eSTREAM Portfolio. (2008/4/24)
• We had a talk focused on theoretical side of CryptMT ver. 3 at SAC2007. (2007/8/17)
• CryptMT ver. 3 is one of the candidates of eSTREAM phase 3. (2007/4/1)

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

• Papers and source files are in CryptMT page in eSTREAM. The source files are written in C to fit to eSTREAM specification, and they can't compile and use as a stand-alone application.
• The slides used in a talk at SAC2007 (sac2007-ohp.pdf.) (I don't know why, but an OSX application preview doesn't show some lines in figures.)
• Proceedings of SAC2007
• C++ source file (free for noncommercial use. see LICENSE.txt.)
  • A class of CryptMT3 and a file encryption application.
  • Source file for Linux: CryptMT3-1.0.tar.gz
  • Source file and dll file for Windows: CryptMT3-1.0.zip

*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.