US 12,388,615 B2
Method for securing a multiple point multiplication operation against side-channel attacks
David Vigilant, Malakoff (FR); Steven Madec, Montigny le Bretonneux (FR); and Mylène Roussellet, Saint Savournin (FR)
Assigned to THALES DIS FRANCE SAS, Meudon (FR)
Appl. No. 18/260,793
Filed by THALES DIS FRANCE SAS, Meudon (FR)
PCT Filed Jan. 11, 2022, PCT No. PCT/EP2022/050455
§ 371(c)(1), (2) Date Jul. 10, 2023,
PCT Pub. No. WO2022/148884, PCT Pub. Date Jul. 14, 2022.
Claims priority of application No. 21305022 (EP), filed on Jan. 11, 2021.
Prior Publication US 2024/0313942 A1, Sep. 19, 2024
Int. Cl. H04L 9/00 (2022.01); H04L 9/30 (2006.01)
CPC H04L 9/003 (2013.01) [H04L 9/3066 (2013.01); H04L 2209/046 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for securing against side channel attacks via execution of an elliptic curve cryptographic process comprising a multiple points multiplication operation computing a multiple points multiplication operation result R=Σi=1ndi·Pi with n an integer, n>=1, di being predetermined scalar values, Pi being points of an elliptic curve over a finite field defined by parameters (F, E, G, N) together with the point addition law where F is a field over which is defined the curve, E is an equation of the curve, G is a base point in E over F and N is the order of the base point G,
said method being performed by a cryptographic device and comprising:
generating (S1) a masking value iRand;
multiplicatively masking (S2) each predetermined scalar value d1 with said generated masking value iRand to obtain masked scalars di′ with i in {1, . . . ,n};
computing (S3) a masked multiple points multiplication operation result R′=Σi=1ndi′·Pi with i in {1, . . . ,n}; and
obtaining (S4) said multiple points multiplication operation result R by unmasking said masked multiple points multiplication operation result R′.