The authenticity of a product associated with a host device is verified through a process. The product contains, in segments of a non-volatile memory, several different functions stored in ciphered fashion. The process involves, in a first phase, the sending by the host device of a control signal for executing a function, with the product functioning to decipher the function and store the unciphered function in the non-volatile memory. The process further involves, in a second phase, the sending by the host device of a control signal for causing execution of the deciphered function, with the product functioning to execute the function and send a result of this execution back to the host device. The host device evaluates the received result to verify product authenticity.