Method of increasing the security of digital signatures

The inventive method which serves to increase the security of digital signatures is based on the tight coupling between the display device A and chip card C. That is, the chip card C knows the public key of the display unit AV and the display device A knows the public key of the smart card CV , DOLLAR A According to the invention the encrypted by the display unit data to be transmitted before they are transmitted to the smart card C with the secret key of the display instrument AS and the public key of the smart card CV and after their transmission in the IC card C with the secret key of the smart card CS and the public key of the display device AV decrypted. DOLLAR A The desired signature will only be generated when the stored in the smart card C public key of the display device AV corresponds with the secret key of the display device AS.