A new protocol for user awareness in card based shopping

Consciously or unconsciously, we are using many kinds of “cards” in our daily lives. Among them, credit card, cash card, driving license, etc., are as important as our wallets. To protect the card holder from malicious use of his/her cards, it is necessary to authenticate the card user. For this purpose, a common practice is to ask the user to provide some key information (usually password) known or possessed only by the true card holder. However, if the key information is leaked, the third party may still use the card easily. The purpose of this paper is to propose a new protocol for authenticating the card user. The basic idea is to re-shape the bio-image (e.g. photograph) of the true card holder, store it in the card, and reconstruct the original image when the card is used. By doing so, the human operator can identify the card user directly based on the reconstructed image, and the true card holder can be protected effectively.