k of n aides to n ministers leak information; ministers only know whether other ministers' aides leaked (not their own)
124488
Spivak Chapter 2, problems 27 (and 28)
65323
What made the Ministry admit Sirius was innocent?
128850
Proving an encrypted message contains (but does not 100% consist of) a plain-text message?
51024
Conveying "under the radar" in a less colloquial way
100640
K out of N encryption
130265
What's a word that means to 'intentionally withhold information'?
5955
"I leaked nothing to nobody." - SAE? AAVE? Deliberate double negative?
138601
There are $2n+1$ people. For each $n$ people there is somebody who is friend with each of them. Prove there is a "know-them-all" person.
135042
Non-citation of basic knowledge
93261
Stacktrace information preserving paths of original source
130885
Information of the user in comments
54861
The Three Princesses (distinguishing truth-teller with 1 question)
61955
“the top levels of government” -- why not "of THE government"?
124442
Provide information "on", "of" or "about" something?
93724
How to substantiate the claim that something is not known?
24376
Why is the K silent in 'know' and 'knotty' etc?
64051
Is there a term for a masked / veiled question to find sensitive information?