In a system for reading data encoded on a single, secure, personal, portable database of private information, such as an optical memory card, a method of interaction between an optical card user, a broker and an agency seeking a transaction with the card user. The user is provided with a blank optical memory card which he encodes with the user's personal transactional information such as credit card numbers. The agency and user are provided with access to a transaction site. The user is able to use the single, secure medium to conduct many transactions. The user selects the encoded information that is needed to conduct the transaction with an agency. The information is read and transmitted to a broker who completes the transaction. Here, the agency is not provided with access to the information and the information is not stored in company or network database or on a network.