Interesting they both say "Official Sha3" and "by its designers", which as I remember it isn't that accurate. Keccak was chosen and then NIST added what is affectionately known as the 'mystery padding' before certification. What we know as official is not the way the designers submitted the proposal.<p>This isn't an attempt at a scary accusation, but as a pedant, this got me.<p>For those wondering, here is an explanation by a commenter:<p><pre><code> The padding change is the only difference, this allows future tree hashing modes as well as the current SHAKE outputs to generate different digests given the same security parameters and message inputs. Up to 4 additional bits are added, which keeps the full padding inside a byte boundary, making implementations with octet only input able to switch to SHA-3 from Keccak with change to only a single line of code.
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<a href="https://crypto.stackexchange.com/questions/10645/are-nists-changes-to-keccak-sha-3-problematic" rel="nofollow">https://crypto.stackexchange.com/questions/10645/are-nists-c...</a><p><a href="https://cdt.org/insights/what-the-heck-is-going-on-with-nist%E2%80%99s-cryptographic-standard-sha-3/" rel="nofollow">https://cdt.org/insights/what-the-heck-is-going-on-with-nist...</a><p>ketccak team's response: <a href="https://keccak.team/2013/yes_this_is_keccak.html" rel="nofollow">https://keccak.team/2013/yes_this_is_keccak.html</a>