We currently have three site-specific close reasons:
- Requests for analyzing or decyphering a block of data are off-topic here, as the results are rarely useful to anyone else.
- Requests for reference recommendations are off-topic here. For details, see: Do we want “literature recommendations” and similar “list/subjective questions”?
- Questions on mathematics are off-topic unless they relate directly to cryptography. These questions can usually be asked on Mathematics Stack Exchange.
There is unfortunately no way to search custom close reasons or retrieve them from the API, which makes it impractical to make any statistics as to the use of the predefined site-specific close reasons or analyze the free-form close reasons that people have been using.
I see a lot of questions which involved a cryptography primitive, but that are off-topic on this site, and would instead:
- be on-topic on Stack Overflow, because the question is fundamentally a programming problem (for a computation which happens to involve a cryptographic primitive);
- be on-topic on Security Stack Exchange, because the question is fundamentally about achieving a security policy (which happens to rely on a cryptographic primitive for implementation).
My feeling as a frequent close reviewer is that each of these is more common than math questions, with Security about as common as reference recommendations, and Stack Overflow more than that and more and more so.
Therefore, please add two custom close reasons, one for each of these two cases. (When this site graduates, I expect that these close reasons would become migration targets; beta sites don't get migration targets, though moderators can migrate to any site.)