caa a22 4500 606148833 CHVBK 20210128100531.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00145-013-9159-4 doi (NATIONALLICENCE)springer-10.1007/s00145-013-9159-4 Improved Single-Key Attacks on 8-Round AES-192 and AES-256 [Elektronische Daten] [Orr Dunkelman, Nathan Keller, Adi Shamir] AES is the most widely used block cipher today, and its security is one of the most important issues in cryptanalysis. After 13 years of analysis, related-key attacks were recently found against two of its flavors (AES-192 and AES-256). However, such a strong type of attack is not universally accepted as a valid attack model, and in the more standard single-key attack model at most 8 rounds of these two versions can be currently attacked. In the case of 8-round AES-192, the only known attack (found 10 years ago) is extremely marginal, requiring the evaluation of essentially all the 2128 possible plaintext/ciphertext pairs in order to speed up exhaustive key search by a factor of 16. In this paper we introduce three new cryptanalytic techniques, and use them to get the first non-marginal attack on 8-round AES-192 (making its time complexity about a million times faster than exhaustive search, and reducing its data complexity to about 1/32,000 of the full codebook). In addition, our new techniques can reduce the best known time complexities for all the other combinations of 7-round and 8-round AES-192 and AES-256. International Association for Cryptologic Research, 2013 AES nationallicence Cryptanalysis nationallicence Single-key attacks nationallicence Multiset tabulation nationallicence Differential enumeration nationallicence Key bridging nationallicence Dunkelman Orr Computer Science Department, University of Haifa, 31905, Haifa, Israel aut Keller Nathan Department of Mathematics, Bar-Ilan University, 52900, Ramat Gan, Israel aut Shamir Adi Faculty of Mathematics and Computer Science, Weizmann Institute of Science, P.O. Box 26, 76100, Rehovot, Israel aut Journal of Cryptology Springer US; http://www.springer-ny.com 28/3(2015-07-01), 397-422 0933-2790 28:3<397 2015 28 145 https://doi.org/10.1007/s00145-013-9159-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00145-013-9159-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dunkelman Orr Computer Science Department, University of Haifa, 31905, Haifa, Israel aut NATIONALLICENCE 700 1- Keller Nathan Department of Mathematics, Bar-Ilan University, 52900, Ramat Gan, Israel aut NATIONALLICENCE 700 1- Shamir Adi Faculty of Mathematics and Computer Science, Weizmann Institute of Science, P.O. Box 26, 76100, Rehovot, Israel aut NATIONALLICENCE 773 0- Journal of Cryptology Springer US; http://www.springer-ny.com 28/3(2015-07-01), 397-422 0933-2790 28:3<397 2015 28 145