While I see the usefulness of those tags for the specific purpose, I doubt the overall usefulness (as opposed to cluttering our tags unnecessarily). Quoting our help center:
You should always favor existing tags; only create new tags when you feel you can make a strong case that your question does cover a new topic that nobody else has asked about before on this site.
(emphasis mine). I know there's room for interpretation. But a tag that's too rarely used doesn't make a good tag IMHO.
So, picking the list given in Nicolas' answer (which is far from being complete, note the "etc."), we should first consider how useful each tag would really be. Not just for the question at hand (linked to from the question body above), but in general. A possible approach to that could be skimming/keyword-searching existing questions whether any might need such.
In so far I agree with Nicolas: we shouldn't create "pairs" to distinguish between "secured or not". Nowadays it's usually clear that the secured variant is to be preferred. But preferences should be part of the question body – and the security tag be reserved for cases where it's "real important" (i.e. a core requirement).
TL;DR: Could we agree on
- only one tag per tag (ahem, e.g. no pairs like
https – or in my experience we'd end up with tons of questions using both)
- instead, declare preferences in the question body – plus use the security where it marks a "core requirement" (otherwise always interpret the question as "secured to be preferred")
- first evaluate which tags are really useful (i.e. not wildly add tags for each protocol just because there's one question matching it)