Multidimensional Meet-in-the-Middle Attacks on Reduced-Round TWINE-128

Abstract

TWINE is a lightweight block cipher designed for multiple platforms and was proposed at Selected Areas in Cryptography, 2012. The number of rounds of TWINE is 36 and the most powerful attack given by the designers is the impossible differential attack against 24 rounds of TWINE-128 whose time complexity is 2115.10 encryptions and data complexity is 252.21 blocks. The best attack known so far is the biclique attack on the full round cipher with a time complexity of 2126.82 and data complexity of 260. However the time complexity of biclique attack is near exhaustive search and data needed for the attack is near the whole codebook.