Advertisement

Differential Cryptanalysis of a Reduced-Round SEED

  • Hitoshi Yanami
  • Takeshi Shimoyama
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2576)

Abstract

We analyze the security of the SEED block cipher against differential attacks. SEED is a 16-round Feistel cipher developed by the Korea Information Security Agency. The SEED proposers estimated their cipher against differential cryptanalysis in a self-estimation document and found a six-round differential characteristic with probability 2-130. We present an improved method of examining the differential characteristics of SEED and show three six-round differential characteristics with probability 2-124. These characteristics allow us to attack sevenround SEED, which surpasses the proposers estimation. Our differential attack needs 2126 chosen-plaintext pairs and 2126 computations of the F function to deduce the subkey used in the last round of seven-round SEED.

Keywords

symmetric block cipher SEED differential attack characteristic probability 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    E. Biham and A. Shamir, Differential Cryptanalysis of DES-like Cryptosystems, Journal of Cryptology, Vol. 4, No. 1, 3–72, 1991.zbMATHCrossRefMathSciNetGoogle Scholar
  2. 2.
    E. Biham and A. Shamir, Differential Cryptanalysis of Feal and N-Hash, EUROCRYPT’ 91, Lecture Notes in Computer Science 547, 1–16, 1991.Google Scholar
  3. 3.
    Korean Information Security Agency, A Design and Analysis of SEED, 1998 (in Korean). (http://www.kisa.or.kr/technology/sub1/128-seed.pdf)
  4. 4.
    Korean Information Security Agency, ANNEX: The Analyses on SEED, seed analysis.doc, 2000. (http://www.kisa.or.kr/seed/algorithm.htm)
  5. 5.
    Korean National Body, Contribution for Korean Candidates of Encryption Algorithm (SEED), ISO/IEC JTC1 SC27 N2563, seed english.doc, 2000. (http://www.kisa.or.kr/seed/algorithm.htm)
  6. 6.
    H. Lipmaa and S. Moriai, Efficient Algorithms for Computing Differential Properties of Addition, FSE 2001, Lecture Notes in Computer Science 2355, 336–350, 2002.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 203

Authors and Affiliations

  • Hitoshi Yanami
    • 1
  • Takeshi Shimoyama
    • 1
  1. 1.FUJITSU LABORATORIES LTDNakahara-kuJapan

Personalised recommendations