5. The non-adjacent form for the elliptic scalar multiplication

The motivation to use the signed digit representation of a scalar v, in a scalar multiplication vP, is the computation of the subtraction and addition of the points lying on elliptic curve E which has the same efficient. A signed digit representation of <sup>v</sup> is given by <sup>v</sup> <sup>¼</sup>∑<sup>l</sup> i � ¼ 1 0ei2<sup>i</sup> , where ei ∈ f0; �1g will be explained in this section with more details. The signed digit representation forms the nonadjacent form (NAF) [1, 9, 10] which is given in the next algorithm.
