Paper 2021/157

Sycon: A New Milestone in Designing ASCON-like Permutations

Kalikinkar Mandal, Dhiman Saha, Sumanta Sarkar, and Yosuke Todo


ASCON is one of the elegant designs of authenticated encryption with associated data (AEAD) that was selected as the first choice for lightweight ap- plications in the CAESAR competition, which also has been submitted to NIST lightweight cryptography standardization. ASCON has been in the literature for a while, however, there has been no successful AEAD which is secure at the same time lighter than ASCON. In this article, we have overcome the challenge of constructing a permutation that is lighter than the ASCON permutation while ensuring a similar performance, and based on which we achieve a more lightweight AEAD which we call Sycon. Extensive security analysis of Sycon confirms that it provides the same level of security as that of ASCON. Our hardware implementation result shows that the Sycon permutation has 5.35% reduced area, compared to the ASCON permutation. This leads to a remarkable area reduction for Sycon AEAD which is about 14.95% as compared to ASCON AEAD. We regard the Sycon as a new milestone as it is the lightest among all the AEADs belonging to the ASCON family.

Available format(s)
Secret-key cryptography
Publication info
Published elsewhere. Minor revision. Journal of Cryptographic Engineering
ASCONLightweight cryptographyAEADHardware implementationDiffusionS-box
Contact author(s)
sumanta sarkar @ gmail com
2021-09-27: revised
2021-02-17: received
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Short URL
Creative Commons Attribution


      author = {Kalikinkar Mandal and Dhiman Saha and Sumanta Sarkar and Yosuke Todo},
      title = {Sycon: A New Milestone in Designing {ASCON}-like Permutations},
      howpublished = {Cryptology ePrint Archive, Paper 2021/157},
      year = {2021},
      note = {\url{}},
      url = {}
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