Cryptanalysis of 249-, 250-, ..., 256-Bit Key HyRAL via Equivalent Keys

スポンサーリンク

概要

• 論文の詳細を見る

• HyRAL is a blockcipher whose block size is 128bits, and it supports the key lengths of 128, 129, ..., 256bits. The cipher was proposed for the CRYPTREC project, and previous analyses did not identify any security weaknesses. In this paper, we first consider the longest key version, 256-bit key HyRAL, and present the analysis in terms of equivalent keys. We first show that there are 251.0 equivalent keys (or 250.0 pairs of equivalent keys). Next, we propose an algorithm that derives an instance of equivalent keys with the expected time complexity of 248.8 encryptions and a limited amount of memory. Finally, we implement the proposed algorithm and fully verify its correctness by showing several instances of equivalent keys. We then consider shorter key lengths, and show that there are equivalent keys in 249-, 250-, ..., 255-bit key HyRAL. For each of these key lengths, we present the expected time complexity to derive an instance of equivalent keys.

著者

• Iwata Tetsu

  Dept. Of Computational Science And Engineering Nagoya University

• YANAGIHARA Shingo

  Dept. of Computational Science and Engineering, Nagoya University

• ASANO Yuki

  Dept. of Computational Science and Engineering, Nagoya University

関連論文

• Side Channel Attacks on Message Authentication Codes (特集:ユビキタス社会を支えるコンピュータセキュリティ技術)
• How to Construct Super-Pseudorandom Permutations with Short Keys(Symmetric Cryptography,Cryptography and Information Security)
• Further More on Key Wrapping
• Improving the Permutation Layer of Type 1, Type 3, Source-Heavy, and Target-Heavy Generalized Feistel Structures
• Cryptanalysis of 249-, 250-, ..., 256-Bit Key HyRAL via Equivalent Keys
• Security of Hash-then-CBC Key Wrapping Revisited
• Side Channel Attacks on Message Authentication Codes
• Side Channel Attacks on Message Authentication Codes

スポンサーリンク