Stack Exchange network consists of 177 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Do we really need a tag cryptography? Seems redundant as most (all?) questions should be on that topic anyway.
I've added this to the blacklist, no need for the tag to exist on this site.
No. E.g. the IT security site doesn't have a [security] tag either.