Important meaning; where the most research is being focussed. Maybe because a break-though seems possible or a break-through would have big consequences.

Any questions that are being researched vigorously?

  • $\begingroup$ If you'd asked a few week back, I'd have said NIZKs from worst-case assumptions. But this was recently solved by Peikert and Sheihan: eprint.iacr.org/2019/158. $\endgroup$ – Occams_Trimmer Jun 6 '19 at 15:32
  • $\begingroup$ @Occams_Trimmer Would a new open question be efficient NIZKs from worse case assumptions? $\endgroup$ – WeCanBeFriends Jun 6 '19 at 15:35