gistfile1.txt

// encode to m * legendre(m|p)
if (encode_m) {
      // need to encode the message given that p = 2q+1
      var y = m.add(BigInt.ONE);
      // euler criterion to determine quadratic residuosity
      var test = y.modPow(pk.q, pk.p);
      if (test.equals(BigInt.ONE)) {
    	  this.m = y;
      } else {
    	  this.m = y.negate().mod(pk.p);
      }
    } else {
      this.m = m;
    }