15
Aug 13

Point 'addition' on elliptic curves is both commutative P + Q = Q + P and associative (P + Q) + R = P + (Q + R)

So when point P on an elliptic curve is multiplied by a scalar k, should it be explained as 'p added to itself k – 1 times' or 'p added to itself k times'?

Which definition of scalar multiplication on elliptic curves is right and why? Email me via mathpedagogy-research A T yahoo D O T com

======== k – 1 times ========

If point P on EC is added to itself (k-1) times then we obtain a new point kP on elliptic curve and kP is termed as the scalar multiplication of point P by scalar k.
Source: http://www.ijcsi.org/papers/IJCSI-8-1-131-137.pdf

The fundamental operation for generating a finite abelian group over an elliptic curve is the addition of two points on it. If point P on EC is added to itself (k-1) times then we obtain a new point kP on elliptic curve and kP is termed as the scalar multiplication of pointP by scalar k.
Source: http://www.ijcsi.org/papers/IJCSI-8-1-131-137.pdf

Point iteration is adding a point to itself multiple times. If a point is added to itself k-1 times, where k is a positive integer then point iteration is represented as: [k]P=P+P+……..+P (k – 1 times).
Source: http://dijiang.mobicloud.asu.edu/snac/document/ECC-parings-portable.pdf

Scalar point multiplication is the major building block of all elliptic curve cryptosystems, an operation of the form where k is a positive integer and P is a point on the elliptic curve. Calculating gives the result of adding the point P to itself for exact k-1 times, which results in another point Q on the elliptic curve. AND ALSO Scalar point multiplication is one of the major buildings of ECC block. An operation of form where is a positive integer, P is a point on the curve. The idea is adding the point P to itself k – 1 times to get the resulted point Q.
Source: http://www.ijser.org/paper/Make-a-Secure-Connection-Using-Elliptic-Curve-Digital-Signature.html

... multiplication operation computes the multiple Q = kP, which corresponds to adding P to itself k − 1 times
Source: http://eprint.iacr.org/2013/131.pdf

====== k times ======

Cryptographic schemes based on ECC rely on scalar multiplication of elliptic curve points. As before given an integer k and a point P... scalar multiplication is the process of adding P to itself k times.
Source: http://www.secg.org/collateral/sec1.pdf

The scalar integer multiplication of an elliptic curve point, P is defined as the process of adding P to itself k times. Q = k P.