DOI QR코드

DOI QR Code

Higher order DC for block ciphers with 2-block structure

2-블록 구조 블록 암호에 대한 고차 차분 공격

  • Published : 1999.09.01

Abstract

We study on the security for the block ciphers with 20block structure which have provable security against DC and LC on the view point of higher order DC, 2-block structures are classified three types according to the location of round function such as C(Center)-type R(Right)-type and L(Left)-type We prove that in the case of 4 rounds encryption function these three types provide the equal strength against higher order DC and that in the case of 5 or more rounds R-type is weaker than C-type and L-type.

DC 및 LC에 대하여 증명 가능한 안전성을 제공하는 2-블록 구조를 라운드 함수의 위치에 따라 서 C(Center)-형 R(Right)형 L(Left)-형으로 구분하고 각각에 대한 고차 차분 공격 측면의 안전성을 분 석한다. 4라운드 암호화 함수인 경우 세가지 2-블록 구조는 고차 차분 공격에 대하여 동일 한 안전성을 제공한다는 사실을 증명하며 5라운드 이상의 암호화 함수에 대해서는 병렬 연산이 가능한 R-형 구조가 C-형과 l-형에 비해서 계산 효율성은 높지만 고차 차분 공격 측면의 안전성은 떨어진다는 사실을 밝힌 다. We study on the security for the block ciphers with 20block structure which have provable security against DC and LC on the view point of higher order DC, 2-block structures are classified three types according to the location of round function such as C(Center)-type R(Right)-type and L(Left)-type We prove that in the case of 4 rounds encryption function these three types provide the equal strength against higher order DC and that in the case of 5 or more rounds R-type is weaker than C-type and L-type.

Keywords

References

  1. IEICE TRANS. FUNDAMENTALS no.1 Strict evaluation of the maximum average of differential probability and the maximum average of linear probability K. Aoki;K. Ohta
  2. Advances in Cryptology - CRYPTO'90, LNCS 537 Differential cryptanalysis of DES-like Cryptosystems E. Biham;A. Shamir
  3. Journal of Cryptology v.1 no.4 Differential cryptanalysis of DES-like Cryptosystems E. Biham;A. Shamir
  4. Fast Software Encryption'97. LNCS 1267 The interpolation attack on block ciphers T. Jakobsen;L. R. Knudsen
  5. Proceedings of SAC'97 On provable security against differential and linear cryptanalysis in generalized Feistel ciphers with multiple random functions Y. Kaneko;F. Sano;K. Sakurai
  6. Fast Software Encryption '95, LNCS 1008 Truncated and higher order differentials L. R. Knudsen
  7. Communications and Cryptography Higher order derivatives and differential cryptanalysis X. Lai
  8. Advances in Cryptology - Eurocrypt'91, LNCS 547 Markov Ciphers and Differential Cryptanalysis X. Lai;J. Massey;S. Murphy
  9. Advances in Cryptology - Eurocrypt'93, LNCS 765 Linear cryptanalysis method for DES cipher M. Matsui
  10. Fast Software Encryption, LNCS 1039 New Structure of Block Ciphers with Provable Security against Differential and Linear Cryptalaysis M. Matsui
  11. Fast Software Encryption'97, LNCS 1267 New Block Encryption Algorithm MISTY M. Matsui
  12. Skipjack and KEA Algorithm Specifications National Institute of Standards and Technology
  13. Advances in Cryptology - Eurocrypt'94, LNCS 950 Linear Approximation of Block Ciphers K. Nyberg
  14. Journal of Cryptology v.1 no.8 Provable Security against Differential Cryptanalysis K. Nyberg;L. R. Knudsen
  15. Information Security Workshop, Preproceedings Improving the higher order differential attack and cryptanalysis of the KN Cipher T. Shimoyama;S. Moriai;T. Kaneko
  16. Technical Report of IEICE, ISEC 98-4 Higher order differential attack of block ciphers MISTY1,2 M. Sugita