In this paper, we show a polynomial time quantum distinguishing attack against the $(3d-3)$-round version, i.e., we improve the number of rounds by $(d-2)$. We also show a quantum distinguishing attack against the $(d^2-d+1)$-round version in the quantum chosen-ciphertext setting. We apply these quantum distinguishing attacks to obtain key recovery attacks against Type-1 generalized Feistel ciphers.
Category / Keywords: secret-key cryptography / Generalized Feistel cipher, Simon's algorithm, Grover search, Quantum cryptanalysis Date: received 26 Mar 2019 Contact author: tetsu iwata at nagoya-u jp Available format(s): PDF | BibTeX Citation Version: 20190329:131640 (All versions of this report) Short URL: ia.cr/2019/327