2012 | OriginalPaper | Chapter
Three-Subset Meet-in-the-Middle Attack on Reduced XTEA
Authors : Yu Sasaki, Lei Wang, Yasuhide Sakai, Kazuo Sakiyama, Kazuo Ohta
Published in: Progress in Cryptology - AFRICACRYPT 2012
Publisher: Springer Berlin Heidelberg
Activate our intelligent search to find suitable subject content or patents.
Select sections of text to find matching patents with Artificial Intelligence. powered by
Select sections of text to find additional relevant content using AI-assisted search. powered by
This paper presents an improved single-key attack on a block-cipher XTEA by using the three-subset meet-in-the-middle (MitM) attack. Firstly, a technique on a generic block-cipher is discussed. It points out that the previous work applying the splice-and-cut technique to the three-subset MitM attack contains incomplete arguments, and thus it requires a very large data complexity, which is close to the code book. This paper gives a corrected procedure to keep the data complexity small. Secondly, the three-subset MitM attack is applied for reduced-round XTEA, which is a 64-bit block-cipher with 64-round Feistel network and a 128-bit key. 25 rounds are attacked with 9 known plaintexts and 2
120.40
XTEA computations, while the previous best single-key attack only reaches 23 rounds. In the chosen-plaintext model, the attack is extended to 28 rounds with 2
37
chosen-plaintexts and 2
120.38
computations.