SQUARE Attacks on Reduced-Round PES and IDEA Block Ciphers

J. Nakahara Jr; P. S. L. M. Barreto; B. Preneel; J. Vandewalle; H. Y. Kim

Paper 2001/068

SQUARE Attacks on Reduced-Round PES and IDEA Block Ciphers

J. Nakahara Jr, P. S. L. M. Barreto, B. Preneel, J. Vandewalle, and H. Y. Kim

Abstract

This paper reports on variants of the Square attack applied to reduced-round versions of the PES and IDEA block ciphers. Attacks on 2.5 rounds of IDEA require $3 \cdot 2^{16}$ chosen-plaintexts and recover 78 key bits. A new kind of attack, the Square related-key attack, is applied on 2.5 rounds of IDEA and recovers 32 key bits, with 2 chosen-plaintexts and related keys. Similar results hold for 2.5 rounds of PES. Implementations of the attacks on 32-bit block mini-versions of both ciphers confirmed the expected computational complexity. Although our attacks do not improve on previous approaches, this report shows new variants of the Square attack on word-oriented block ciphers like IDEA and PES.

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Metadata

Available format(s): PDF PS
Category: Secret-key cryptography
Publication info: Published elsewhere. Unknown where it was published
Keywords: block ciphers cryptanalysis secret-key cryptography
Contact author(s): jorge nakahara @ esat kuleuven ac be
History: 2001-08-22: revised; 2001-08-14: received; See all versions
Short URL: https://ia.cr/2001/068
License: CC BY

BibTeX

@misc{cryptoeprint:2001/068,
      author = {J. Nakahara Jr and P. S. L. M. Barreto and B. Preneel and J. Vandewalle and H. Y. Kim},
      title = {{SQUARE} Attacks on Reduced-Round {PES} and {IDEA} Block Ciphers},
      howpublished = {Cryptology {ePrint} Archive, Paper 2001/068},
      year = {2001},
      url = {https://eprint.iacr.org/2001/068}
}