Koninklijke Philips Corporation N.v.

Jaime Gutierrez

Ludovicus Marinus Gerardus Maria Tolhuizen

Oscar Garcia Morchon

Domingo Gomez

Sandeep Shankaran Kumar

A method of configuring a network device for key sharing and a method for a first network device to determine a shared key are provided. The method of configuring uses a private modulus (p) a public modulus (N), and a bivariate polynomial (f) having integer coefficients, the binary representation of the public modulus and the binary representation of the private modulus are the same in at least key length (b) consecutive bits. Local key material for a network device is generated by substituting an identity number into the bivariate polynomial and reducing modulo the private modulus the result of the substitution to obtain a univariate polynomial. Security may be increased by adding () one or more obfuscating numbers to coefficients of the univariate polynomial to obtain an obfuscated univariate polynomial. In a use phase, the network device determines a shared cryptographic key, by substituting () the identity number of another network device into the univariate polynomial and reducing modulo the public modulus and reducing modulo a key modulus.

Key sharing device and system for configuration thereof

A method of configuring a network device for key sharing, the method comprising obtaining () in electronic form at least two parameter sets, a parameter set comprising a private modulus (p) a public modulus (N), and a bivariate polynomial (f) having integer coefficients, the binary representation of the public modulus and the binary representation of the private modulus are the same in at least key length (b) consecutive bits, generating local key material for the network device comprising obtaining () in electronic form an identity number (A) for the network device, and for each parameter set of the at least two parameter sets obtaining a corresponding univariate polynomial, by determining, using a polynomial manipulation device, a univariate polynomial from the bivariate polynomial of the parameter set by substituting () the identity number into said bivariate polynomial, and reducing the result of the substitution modulo the private modulus of the parameter set, and electronically storing () at the network device the generated local key material, the generated local key material comprising the public modulus of each parameter set and the corresponding univariate polynomial of each parameter set.

Growing community of inventors

Eindhoven, Netherlands

Jaime Gutierrez