I'm posting this as an outsider to Crypto.SE. The odd time that I stray over here from Security.SE (where I'm a 10k user) I'm often greeted by all the usual stereotypes of elitist mathematicians.

In particular, this question was in the weekly newsletter, but when I clicked it I was rather shocked to find this comment and this comment which are almost mocking the OP for not being a mathematician (you actually expect the OP to be satisfied with a link to wikipedia/cyclic_permutation_group ?).

To me this question seemed like a great way to put some info out there and clear up a common misconception through a question that's likely to get a lot of Google hits (it's already at almost 1,000 views). Instead a user is greeted with sneer and disdain as the first comment.

So my question to the Crypto.SE community is: is this how you want the rest of the SE network to view Crypto.SE? By not moderating comments like that, you are making a decision...


Since the most offensive comment above was deleted, I'll broaden the scope of this question:

If somebody comes in with a genuine crypto-related question, but very little understanding of mathematics, are they welcome here?

I guess this is a call to

  • be a little quicker to flag/moderate dismissive comments (and post an encouraging follow-up comment while waiting for the flag to be dealt with).
  • When posting an answer, pay more attention to the knowledge-level that the question was asked at. Many answers on this site are wonderful, others are daunting. Maybe as a rule of thumb for a non-technical OP, post an answer directed at the OP, then a horizontal rule, then delve into group theory and whatever else you feel is "the correct answer".


Another perfect example of this that I just stumbled into: How is injective, inverse, surjective & oneway related to cryptography?

This question received multiple downvotes, and based on @RichieFrame's comment it seems that the OP was mocked for asking it.

  • 1
    $\begingroup$ FWIW, one of the two comments has been flagged as "not constructive". As of right now, that flag was only added 14 minutes ago. The comment in question was added 19 hours ago. Is your question why is there such a gap between the comment being added and the flag being raised? $\endgroup$
    – mikeazo
    Apr 6, 2016 at 0:56
  • $\begingroup$ Not really. This is not the first time I've seen comments like this here. My question is more of a discussion-point for the community. In particular the trend of taking a question clearly posed by a curious layman and giving an answer that requires an undergrad in math to understand. $\endgroup$ Apr 6, 2016 at 1:00
  • 1
    $\begingroup$ How do you feel about the accepted answer on that particular question? $\endgroup$
    – mikeazo
    Apr 6, 2016 at 1:05
  • $\begingroup$ Yeah, the accepted answer is good. Nice easy-to-follow explanation. $\endgroup$ Apr 6, 2016 at 1:07
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    $\begingroup$ One of the comments you linked to has since been removed. Could you explain the gist of it? The one that still exists seems like a good addition to the very bare-bones second answer. $\endgroup$
    – otus
    Apr 6, 2016 at 8:49
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    $\begingroup$ @otus It was a rude, snarky comment to the effect of "I know we're supposed to be helping people, but if you have to ask this question....". $\endgroup$ Apr 6, 2016 at 11:37
  • $\begingroup$ Don’t get me wrong, but …I'm often greeted by all the usual stereotypes of elitist mathematicians… is a bit of a slap in the face for all those not being such stereotypes, elitists, and/or mathematicians – but that might just be me (personal impression/opinion; not speaking as a mod). $\endgroup$
    – e-sushi
    Apr 9, 2016 at 15:15
  • $\begingroup$ @e-sushi Haha. I'm also often greeted by helpful, caring commenters, but that doesn't really make for a good meta question ;-) $\endgroup$ Apr 9, 2016 at 15:23
  • $\begingroup$ Valid point… ;) $\endgroup$
    – e-sushi
    Apr 9, 2016 at 15:26
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    $\begingroup$ Good topic. Im amazed at how often SE answers and comments are used to say "don't ask this" or "you asked it wrong" or "this question isn't welcomed here", versus actually talking about the topic of the question within the realm of the SE. Before you judge me as "one of those", i posted a simple crypto question to try to understand it's weaknesses and was told not to re-invent the wheel (wasn't planning on it) and that this wasnt the place to ask the question?! crypto.stackexchange.com/questions/34474/… $\endgroup$
    – Alan Wolfe
    Apr 12, 2016 at 16:22

3 Answers 3


I'm one of those pesky mathematicians. Here's my attempt to explain what is going on.

I think the core of the problem is that not everyone reading the answer or the follow up comment will understand the underlying theory that makes it such a neat concise answer (mathematicians like concise statements of truth like this). That's fine and OK, but it's hard to necessarily know what level of explanation is needed.

As a learner, sometimes:

  • What you're asking is more complex/beyond your level than you necessarily realized. In this case while you will probably get an answer you might not understand it and it is on you to ask the right follow up questions in appropriate places. That said, SE is quite good at optimizing for accessible explanations of ideas, since they tend to be more popular.
  • Sometimes you forget to specify what you need. In my experience SE is quite good at adapting to the level of the asker and, indeed, answering the question that should have been asked sometimes :)
  • Sometimes (usually it is obvious) the answer would require an explanation that would fill a book.

Negotiating these situations is always a bit tricky. If in doubt, the "be nice" rule applies, in my opinion.

I personally see nothing wrong with questions along the lines of "I read {thing} in {this answer} and I'm not sure what it means". The only debate is likely to be around where they belong. Maybe here, maybe maths, maybe cs.


The comment denigrating the OP for asking a question was out-of line if it was as described in the comments. However, the other one seems fine.

I do not think we should assume the asker lacks mathematical background. That can seem at least as rude as the converse if the assumption is incorrect. Instead, any answer will necessarily assume some level, which the writer is free to choose. The OP can ask for clarification in comments if the answer is not understandable. Other answers can expand if needed.

Sometimes that clarification may be a pointer off-site resources, because this is after all a site about cryptography rather than math in general. As long as it is not done rudely, I see no problem there.

By not moderating comments like that, you are making a decision...

[...] be a little quicker to flag/moderate dismissive comments (and post an encouraging follow-up comment while waiting for the flag to be dealt with).

In the end we are all a part of moderating the site, even casual readers. Yes, we should flag comments if they are problematic and the mods will take a look. Unfortunately, many questions receive little attention so any comment will take time to even notice. (Maybe not the case here, I guess, if it was a popular question.)

If somebody comes in with a genuine crypto-related question, but very little understanding of mathematics, are they welcome here?

Yes, they definitely should be. However, they may need to brush up on the relevant concepts to fully understand answers, if the question is complex enough (under the hood).


Disclaimer: Hereby I'll speak on my behalf and personal opinion. This might not reflect Crypto.SE community and I will not assume such assumption.

I don't think Mathematicians in Crypto.SE are being elitists. As a former maths teacher, I can tell there are some part of cryptography that require more than the usual background.

Thus we have a problem: What is the minimal maths background required to understand an answer ?

I would expect it to be around post-Highschool, pre-bachelor's degree, something that would give :

  1. modulus operations.
  2. exponentiation and logarithm.
  3. logical operations (such as xor).

These are, in my humble opinion, the minimum knowledge required. I also think that a more advanced user is expected to know about Z/pZ and the group theory (Diffie-Hellman ...) Which is why I'm not shocked by yyyyyy's answer which I find quite elegant and deserve to be upvoted.

The problem is not are we being elitist, it is rather that:

  1. we expect at least a common base which sometimes is not met.
  2. we need to be able to adapt ourselves to provide a satisfactory answer to the question. In the case you mentioned, I think both answers are interesting, one being a bit more high level than the second. The sole and only problem is being understandable (and understood).

Here is another question that was closed (because though too broad) while still being interesting. This comment could be seen as slightly offensive. But it also shows that we expects the questioner to do some research before asking. This kind of behaviour could be is also mentioned here by (Otus):

many people only ask the one question and are gone, perhaps even before seeing answers if it takes a day or more.

Thus no, I do not think we are being elitist and our mod team is doing a great job to maintain such the quality of Crypto.SE.

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    $\begingroup$ Re: your disclaimer, votes will decide if it reflects the opinion of the community. ;) $\endgroup$
    – otus
    Apr 6, 2016 at 12:13

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