## Cryptology ePrint Archive: Report 2011/453

Practical Complexity Differential Cryptanalysis and Fault Analysis of AES

Michael Tunstall

Abstract: This paper presents a survey of practical complexity differential cryptanalysis of AES and compares this to attacks that have been proposed for differential fault analysis. Naturally, the attacks in each vein of research are applicable in the other but use different models. In this paper we draw from both topics to improve attacks proposed in the literature. We re-evaluate the so-called Square attack and the use of impossible differentials in terms of differential fault analysis using a weaker model than previously considered in the literature. Furthermore, we propose two new attacks applicable to both differential cryptanalysis and differential fault analysis. The first is a differential cryptanalysis of four-round AES based on a differential that occurs with a non-negligible probability. The second is an application of the Square attack to a five-round AES that requires $2^8$ ciphertexts and a time complexity equivalent to approximately $2^{37}$ AES encryptions.

Category / Keywords: implementation /

Date: received 18 Aug 2011, last revised 13 Nov 2011

Contact author: tunstall at cs bris ac uk

Available format(s): PDF | BibTeX Citation

Note: To appear in the Journal of Cryptographic Engineering

Short URL: ia.cr/2011/453

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