International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Related-Key Boomerang and Rectangle Attacks

Jongsung Kim
Seokhie Hong
Bart Preneel
Eli Biham
Orr Dunkelman
Nathan Keller
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Abstract: This paper introduces the related-key boomerang and the related-key rectangle attacks. These new attacks can expand the cryptanalytic toolbox, and can be applied to many block ciphers. The main advantage of these new attacks, is the ability to exploit the related-key model twice. Hence, even ciphers which were considered resistant to either boomerang or related-key differential attacks may be broken using the new techniques. In this paper we present a rigorous treatment of the related-key boomerang and the related-key rectangle distinguishers. Following this treatment, we devise optimal distinguishing algorithms using the LLR (Logarithmic Likelihood Ratio) statistics. We then analyze the success probability under reasonable independence assumptions, and verify the computation experimentally by implementing an actual attack on a 6-round variant of KASUMI. The paper ends with a demonstration of the strength of our new proposed techniques with attacks on 10-round AES-192 and the full KASUMI.
  title={Related-Key Boomerang and Rectangle Attacks},
  booktitle={IACR Eprint archive},
  keywords={secret-key cryptography / Related-key Boomerang Attack, Related-Key Rectangle Attack, AES, KASUMI.},
  note={Submitted to a journal in October 2009 14621 received 12 Jan 2010},
  author={Jongsung Kim and Seokhie Hong and Bart Preneel and Eli Biham and Orr Dunkelman and Nathan Keller},