摘要 |
A method for preventing secret code manipulation in a data processing device, such as a smart card, to which a presented code is applied. Prior to implementation of a code transforming function in the processing device, the secret code is transformed into a transformed secret code in the card. For each use of the card, the presented code is transformed into a transformed presented code in accordance with the implemented transformation function. A comparison of the transformed secret code with the transformed secret code in the card is then performed. |