New Results on Boomerang and Rectangle Attacks

The boomerang attack is a new and very powerful cryptanalytic technique. However, due to the adaptive chosen plaintext and ciphertext nature of the attack, boomerang key recovery attacks that retrieve key material on both sides of the boomerang distinguisher are hard to mount. We also present a method for using a boomerang distinguisher, which enables retrieving subkey bits on both sides of the boomerang distinguisher. The rectangle attack evolved from the boomerang attack. In this paper we present a new algorithm which improves the results of the rectangle attack.Using these improvements we can attack 3.5-round SC2000 with 267 adaptive chosen plaintexts and ciphertexts, and 10-round Serpent with time complexity of 2173.8 memory accesses (which are equivalent to 2165.3 Serpent encryptions) with data complexity of 2126.3 chosen plaintexts.

[1]  Eli Biham,et al.  Differential Cryptanalysis of DES Variants , 1993 .

[2]  Eli Biham,et al.  Cryptanalysis of Skipjack reduced to 31 rounds using impossible differentials , 1999 .

[3]  Lars R. Knudsen,et al.  A Differential Attack on Reduced-Round SC2000 , 2001, Selected Areas in Cryptography.

[4]  Bruce Schneier,et al.  Amplified Boomerang Attacks Against Reduced-Round MARS and Serpent , 2000, FSE.

[5]  David A. Wagner,et al.  Truncated Differentials and Skipjack , 1999, CRYPTO.

[6]  Kazuhiro Yokoyama,et al.  The Block Cipher SC2000 , 2001, FSE.

[7]  Eli Biham,et al.  Miss in the Middle Attacks on IDEA and Khufu , 1999, FSE.

[8]  Louis Granboulan Flaws in differential cryptanalysis of Skipjack , 2001, IACR Cryptol. ePrint Arch..

[9]  Eli Biham,et al.  Differential Cryptanalysis of the Data Encryption Standard , 1993, Springer New York.

[10]  Susan K. Langford,et al.  Differential-Linear Cryptanalysis , 1994, CRYPTO.

[11]  Ross Anderson,et al.  Serpent: A Proposal for the Advanced Encryption Standard , 1998 .

[12]  Eli Biham,et al.  Linear Cryptanalysis of Reduced Round Serpent , 2001, FSE.

[13]  Orr Dunkelman,et al.  Boomerang and Rectangle Attacks on SC2000 , 2001 .

[14]  Lars R. Knudsen,et al.  Truncated and Higher Order Differentials , 1994, FSE.

[15]  Hitoshi Yanami,et al.  Differential and Linear Cryptanalysis of a Reduced-Round SC2000 , 2002, FSE.

[16]  Eli Biham,et al.  The Rectangle Attack - Rectangling the Serpent , 2001, EUROCRYPT.

[17]  David A. Wagner,et al.  The Boomerang Attack , 1999, FSE.

[18]  Mitsuru Matsui,et al.  Linear Cryptanalysis Method for DES Cipher , 1994, EUROCRYPT.