Currently we seem to get quite a lot of capture-the-flag questions. The idea of these capture the flag challenges is not to ask for a solution on the internet, it seems to me. Should we possibly downvote these questions? Should we close them? Or should we treat them like homework questions and only give hints?

If the answer is to close them (or downvote & close them) what should be the close reason? Should we create a new one for it?


I think we should treat those questions just like any other question.

There are multiple reasons for that:

  • Most such questions tend to be rather poor anyways and can then be easily closed under the "analyze ciphertext" reason.
  • There isn't that many things you can do with cryptography and CTFs and so chances are the principles will (unintentionally?) repeat across CTFs. So even if we eg locked a question for the duration of CTF A, a similar challenge may be posed in CTF E and then we'd have to find all prior questions on this topic and soft-delete all answers and lock the questions. And I'm sure we'd miss some with the more basic topics and / or it would be an insurmountable amount of work.
  • It simply isn't our problem. If people decide to ask at a public (and somewhat popular) place (eg here) for a solution, then the organizers should be able to find this (eg via google) and remove / nullify the awarding of points eg starting from the time when the first comment / answer was posted.
  • We can't even be thorough. Recently I was asked questions related to a CTF in the side channel. It turned out that this CTF was only accessible for university students of a certain country. So even if we were made aware of an ongoing CTF it would be hard to verify which questions would fall under it.
  • We probably also don't want to punish honesty in questions. If someone admits that the question is for a CTF and it gets downvoted / closed / locked as result of that, that person likely won't return after such a bad experience. Compare that now to a question where the poster doesn't admit that this is a CTF challenge, where we're nice and helpful and everything and never find out that it was from a CTF. I don't think that "giving the liar the better treatment" in this situation is the right thing to do.
  • $\begingroup$ If somebody really wants to have a policy like they have on Math.SE, please just write your own answer, I'll feature the question and we can have our usual 14-day majority-vote-decides-policy ritual. $\endgroup$ – SEJPM Oct 21 '18 at 19:18
  • $\begingroup$ On Security.SE they propose to : 1: note that the question is part of a CtF challenge in the comments and 2 : "treat it like any other homework problem". What's your opinion on that? $\endgroup$ – Maarten Bodewes Oct 24 '18 at 12:35
  • 1
    $\begingroup$ @MaartenBodewes well, I can't stop people from noting that nor will I remove it and I think we already treat homework questions like other ones, so that aligns nicely. $\endgroup$ – SEJPM Oct 24 '18 at 19:36
  • $\begingroup$ Well, we tend to treat homework questions at least somewhat differently. Generally we seem to require that the asker shows what has already been tried, and we try to nudge the user towards a solution rather than to spell it out directly. But yeah, OK, fine answer otherwise, I'm going to accept it. $\endgroup$ – Maarten Bodewes Oct 24 '18 at 19:40
  • $\begingroup$ @MaartenBodewes I'm inclined to say that we treat anything that looks like homework that way whether it actually is homework / assignment or not and chances are at least some CTF challenges will be indistinguishable from homework questions, so we'll "treat them as homework by accident" or are doing that already. $\endgroup$ – SEJPM Oct 24 '18 at 19:43
  • $\begingroup$ I'm not disagreeing. I was just pointing out that we tend to treat homework questions somewhat different than other questions and that we should probably treat CTF questions as if they are homework questions. If we're already doing that - and it certainly seems to be the case - then all the better :) $\endgroup$ – Maarten Bodewes Oct 24 '18 at 19:55

In my opinion, there is no exact boundary in asking a solution on the internet. If the questioner asks help in a very specific part of the question, is it still asking for the solution on the internet?

If we treat them as homework and give them hints, high probability, we will start to see lots of problems around with many duplicates due to not enough searching on this site. And, one interesting case will be if the question changes the values for each person.

Downvoting, I think, discourages people, but saying off topic is a better idea. Most of them, already request analyzing ciphertext that we have already in off topic.

I say off-topic.


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