Method for producing an electronic device with a disabled sensitive mode, and method for transforming such an electronic device to re-activate its sensitive mode

Abstract

A method is intended for transforming a secure electronic device, associated to a first identifier and having a sensitive mode disabled after production, for a new sensitive use. This method comprises the steps of: (i) externally computing a cipher of the first identifier with a predetermined function fed with this first identifier and a predetermined secret key; (ii) transforming an accessible metal layer of the electronic device to form an activation pattern representing this externally computed cipher of the first identifier; (iii) getting a value representative of this activation pattern into the electronic device; and (iv) computing a second identifier with this transformed electronic device by feeding a reverse function of the predetermined function with this value and this secret key, to trigger a comeback to the sensitive mode if this second identifier is equal to the first identifier.

Dependencies are inferred from the claim text.