Cryptology ePrint Archive: Report 2016/490

Truncated, Impossible, and Improbable Differential Analysis of Ascon

Cihangir Tezcan

Abstract: Ascon is an authenticated encryption algorithm which is recently qualified for the second-round of the Competition for Authenticated Encryption: Security, Applicability, and Robustness. So far, successful differential, differential-linear, and cube-like attacks on the reduced-round Ascon are provided. In this work, we provide the inverse of Ascon's linear layer in terms of rotations which can be used for constructing impossible differentials. We show that Ascon's S-box contains 35 undisturbed bits and we use them to construct 4 and 5-round truncated, impossible, and improbable differential distinguishers. Our results include practical 4-round truncated, impossible, and improbable differential attacks on Ascon. Our best attacks using these techniques break 5 out of 12 rounds. These are the first successful truncated, impossible, and improbable differential attacks on the reduced-round Ascon.

Category / Keywords: secret-key cryptography / cryptanalysis

Original Publication (in the same form): ICISSP 2016 (

Date: received 20 May 2016

Contact author: cihangir at metu edu tr

Available format(s): PDF | BibTeX Citation

Version: 20160520:123130 (All versions of this report)

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