Take the 2-minute tour ×  Can we use a threshold scheme to
construct a (yes/no)-election protocol, such that every voter
can give a positive or negative vote or he can abstain, and such
that only the result of the election is revealed, but the number
of positives, negatives and abstains stays secret?  Are there
some ways to do this without a threshold scheme?  share|improve
this question  1 Answer 1  up vote 5 down vote accepted  A
threshold, additively homomorphic cryptosystems (such as the
threshold variant of paillier) would work just fine for this
sort of system. Each voter would need to prove that their vote
was in the set $\{-1,0,1\}$ instead of the typical $\{0,1\}$.
All of this could be done using the thep library. There is a
page on dealing with negative numbers.  An alternative to this
would be secure multiparty computation. At its core, MPC has the
disadvantage that all parties must be online at the same time.
This can be mitigated by say designating a few (e.g., 5) servers
that perform all the com