A process is provided for deterring the theft of notes equipped with a radio-tag type authenticity check element, capable of returning an item of authenticity information, in response to an authentication request emitted by a check device. Such a process includes the following steps: transmission to the check element of at least one inactivation code, rendering the note invalid; storage and/or transport of the invalid note; and reactivation of the check element, using at least one activation code, depending on the inactivation code, rendering the note valid.