Method for securing the security data of a bank payment card associated with a bank account, which security data are static and comprise the number of said card, identification data of the holder of said card, the expiry date of said card, and a cryptogram , which bank card number and which cryptogram are made up of multiple digits and/or letters, said method comprising the steps of: - only partially inscribing the security data in an intelligible manner on said card so that security data are concealed, said concealed data being formed by: multiple digits and/or letters of the number of said card and/or at least one piece of identification data of the cardholder and/or at least one element of the expiry date and/or at least one digit and/or letter of the cryptogram , - transmitting, to the holder of the card only, a means for disclosing the concealed data, - hiding the concealed data, which are visible on the card, among multiple pieces of data, characterized in that the method comprises the following steps: - arranging the data in a grid , - visibly inscribing the grid on one face of the card , the means for disclosing the concealed data comprising a concealed-data revealer, which takes the virtual form of an augmented reality image generated from a computer application installed on a mobile terminal of the holder of the card , which revealer image is displayed on a screen of said terminal, superimposed on a real image of the grid which is also displayed on said screen, the real image of the card being captured by the optical acquisition means of the mobile terminal , the concealed data being pre-recorded in the memory of the mobile terminal . - only partially inscribing the security data in an intelligible manner on said card so that security data are concealed, said concealed data being formed by: multiple digits and/or letters of the number of said card and/or at least one piece of identification data of the cardholder and/or at least one element of the expiry date and/or at least one digit and/or letter of the cryptogram , - transmitting, to the holder of the card only, a means for disclosing the concealed data, - hiding the concealed data, which are visible on the card, among multiple pieces of data, characterized in that the method comprises the following steps: - arranging the data in a grid , - visibly inscribing the grid on one face of the card , the means for disclosing the concealed data comprising a concealed-data revealer, which takes the virtual form of an augmented reality image generated from a computer application installed on a mobile terminal of the holder of the card , which revealer image is displayed on a screen of said terminal, superimposed on a real image of the grid which is also displayed on said screen, the real image of the card being captured by the optical acquisition means of the mobile terminal , the concealed data being pre-recorded in the memory of the mobile terminal . - arranging the data in a grid , - visibly inscribing the grid on one face of the card , the means for disclosing the concealed data comprising a concealed-data revealer, which takes the virtual form of an augmented reality image generated from a computer application installed on a mobile terminal of the holder of the card , which revealer image is displayed on a screen of said terminal, superimposed on a real image of the grid which is also displayed on said screen, the real image of the card being captured by the optical acquisition means of the mobile terminal , the concealed data being pre-recorded in the memory of the mobile terminal . <EOS>