The invention relates to a process to make secure a personal portable object comprising a body of the personal portable object, a microchip, a printed image and a device to enable said personal portable object to communicate with an entity external to the device. The process includes using an image file and an insertion algorithm to generate an image feature vector Vsi(num), storing the image feature vector Vsi(num) in the microchip, using the printed image obtained by a scanning device to generate an image feature vector Vsi(dig), and using a read-back algorithm to match the image feature vector Vsi(num) and the image feature vector Vsi(dig).