  We present a usability study of the Ascon 1.2 family of cryptographic
algorithms. As far as we know, this is the first published experimental
evaluation aimed at a cryptographic design (i.e. not a specific API) with the
purpose of informing which aspects to standardise. While the results show the
general difficulty of choosing and applying cryptographic algorithms, there are
some more specific insights. These include the possibility of confusing
multiple variants, the relevance of small interfaces, and the desire for
higher-level wrapper functions (e.g. for protocols). Overall, many questions
are still open, including how usability could be integrated into the design and
evaluation of cryptographic algorithms. Our main takeaway is that lightweight
usable cryptography is an open research area that deserves greater focus. For
the review of NISTIR 7977, the standardisation process of Ascon as a FIPS, and
when exploring potential future SPs, the key criterion of usability should be
based on realistic user testing and on triangulation from other methods.
