Method for generating on-board a cryptographic key using a physically unclonable function

A non-transitory computer readable medium storing executable computer code that when executed by a cryptographic device comprising at least one hardware processor, the hardware processor implementing with a Physically Unclonable function and comprising a memory # storing at least one challenge and at least one associated increment number, said associated increment number being a number of incrementation steps to be performed in a predefined cryptographic prime numbers generation algorithm to generate said at least one prime number from a seed obtained from said challenge using said Physically Unclonable function, wherein the executable computer code, when executed by the hardware processor, causes the hardware processor to:

• obtain from said memory a challenge and at least one associated increment number,
• generate a seed by applying said Physically Unclonable function to said obtained challenge,
• generate said at least one prime number from said generated seed by performing said cryptographic prime numbers generation algorithm and by performing therein as many incrementation steps as said obtained at least one increment number,
• generate said cryptographic key from said generated prime number.

A cryptographic device comprising:

• at least one hardware processor implementing a Physically Unclonable function;
• and
• a memory storing at least one challenge and at least one associated increment number, said associated increment number being a number of incrementation steps to be performed in a predefined cryptographic prime numbers generation algorithm to generate said at least one prime number from a seed obtained from said challenge using said Physically Unclonable function, wherein the executable computer code, when executed by the hardware processor, causes the hardware processor to:
• obtain from said memory a challenge and at least one associated increment number,
• generate a seed by applying said Physically Unclonable function to said obtained challenge,
• generate said at least one prime number from said generated seed by performing said cryptographic prime numbers generation algorithm and by performing therein as many incrementation steps as said obtained at least one increment number,
• generate said cryptographic key from said generated prime number.