voting_winneronly.quail

// the leakage is supposed to be $$H(\frac{cases(0)}{2^n},1-\frac{cases(0)}{2^n})$$ where $$cases(0)=\sum_{k=0}^{\lfloor\frac{n}{2}\rfloor}\binom{n}{k}$$

// N is the number of voters
const N:=3;

// the output is the number of votes for one of the two candidates
observable int1 output:=0;

public int32 votecount:=0;

// these bits represent the preferences of each voter
secret array [N] of int1 vote;

// these bits represent the votes received by the voting machine
public array [N] of int1 decl;

// this is just a counter
public int32 i:=0;

// voting
while (i<N) do
  if (vote[i]==0) then
    assign decl[i]:=0;
  else
    assign decl[i]:=1;
  fi
  assign i:=i+1;
od

// count the number of votes for one of the candidates 
for (d in decl) do
  assign votecount:=votecount+d;
od

if (votecount>N/2) then
    assign output:=1;
  else
    assign output:=0;
fi

return;