I think he is trolling, with just enough information to sound correct. The Keccak authors have proposed a "duplex construction"[1][2], using the arbitrary lengt

I think he is trolling, with just enough information to sound correct. The Keccak authors have proposed a "duplex construction"[1][2], using the arbitrary length inputs/outputs and the lack of a output transformation in the sponge construction, that could be used for authenticated encryption. The NIST has yet to included that use case in the SHA-3 standard. So, until there is enough solid understanding for its correct use and tested implementations with that use, it is just a hash function. [1] http://sponge.noekeon.org/ http://sponge.noekeon.org/ (end of the page) [2] http://sponge.noekeon.org/SpongeDuplex.pdf http://sponge.noekeon.org/SpongeDuplex.pdf