Patent · US Active

Encrypted scalar multiplication

US12143467B2 · kind B2 · utility

1Cited by
1References
25Claims
0Family size

Assignee

Inventor

  • Marc Joye · Saint-Maximin-la-Sainte-Baume, FR

Key dates

Filing dateFeb 15, 2022
Grant dateNov 12, 2024
Priority date
Expiry dateFeb 15, 2042

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L9/3026
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

Some embodiments are directed to a computer-implemented method (500) of determining a set of coefficients for homomorphically multiplying an encrypted value by a scalar. The encrypted value is represented by multiple respective value ciphertexts encrypting the value multiplied by respective powers of an even radix. The scalar multiplication is performed as a linear combination of the multiple respective value ciphertexts according to the set of coefficients. The set of coefficients are determined as digits of a radix decomposition of the scalar with respect to the radix. The determined digits lie between minus half the radix, inclusive, and plus half the radix, inclusive. It is ensured that no two subsequent digits are both equal in absolute value to half the radix.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.