Open AccessUnbalanced biclique cryptanalysis of a full round Midori
Author(s) -
Han Guoyong,
Zhang Wenying,
Xing Zhaohui,
Zhao Hongluan,
Lian Jian
Publication year - 2019
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2018.5343
Subject(s) - cryptanalysis , block cipher , mathematics , computer science , algorithm , cryptography
Midori is a family of lightweight block ciphers presented by Banik et al . at Asiacrypt 2015. Biclique cryptanalysis is a typical key‐recovery attack that is proposed to attack the full AES by Bogdanov et al . in ASIACRYPT 2011. The method can attack a great deal of ciphers utilising the main idea of MITM attack and the basic principle of the biclique structure. In this study, the authors first provide an unbalanced biclique attack on full round Midori with partial matching and precomputation. They demonstrate that full round Midori64/128 are not secure against unbalanced biclique attacks. They construct a five‐round 4 × 8 unbalanced biclique on Midori64, with data complexity of 2 36and time complexity of 2 126.25by investigating the simple key schedule and the encryption structure. Furthermore, they present a four‐round 8 × 16 unbalanced biclique on Midori128 with data complexity of 2 72and computational complexity of 2 126.91 . To the best of authors' knowledge, the result is the best single‐key cryptanalytic result of Midori.