I am failing to understand the scope of this proposal. The comments like these:
Since this site was not merged with the security.stackexchange.com one, and that one does cover applied cryptography, as in developers using encryption and building cryptosystems, I would say this should be more in the direction of research / theoretical / conceptual / algorithmical / mathy parts of crypto.
implementation fits SO; applications fit security site.
implementation should be on ITsec; and applications on SU
seem to imply that the scope of the proposal research/theoretical parts of Crypto which is part of theoretical computer science and therefore covered by the scope of cstheory. All of the listed on-topic questions seem to be on-topic for cstheory.
So I think this proposal should be closed, (or alternatively, exclude theoretical crypto questions and then merged into ITSec site, where around half of the questions are tagged with cryptography, encryption, authentication).