Abstract: 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 (p1) a public modulus (N), and a bivariate polynomial (f1) 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 (440) one or more obfuscating numbers to coefficients of the univariate polynomial to obtain an obfuscated univariate polynomial.

Abstract: A method of configuring a network device for key sharing, the method comprising obtaining (410) in electronic form at least two parameter sets, a parameter set comprising a private modulus (p1) a public modulus (N), and a bivariate polynomial (f1) 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 (420) 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 (430) 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 (450)

Abstract: 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 private modulus, and a modulus (p1) a public modulus (N), and a bivariate polynomial (f1) 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 (440) one or more obfuscating numbers to coefficients of the univariate polynomial to obtain an obfuscated univariate polynomial.

Abstract: A system (200) for configuring a network device (300) for key sharing is provided, and a first (300) and second network device configured to determine a shared key between them.

Abstract: A method of configuring a network device for key sharing, the method comprising obtaining (410) in electronic form at least two parameter sets, a parameter set comprising a private modulus (p1) a public modulus (N), and a bivariate polynomial (f1) 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 (420) 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 (430) 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 (450)