A dynamic credit card is provided in which a secure credit card number (e.g., a secret/hidden credit card number) is encoded based on a timing signal (e.g., an internal counter) to provide a dynamic credit card number. This dynamic number may be displayed to a user via a display (e.g., so that online...http://www.google.com.hk/patents/US20080035738?utm_source=gb-gplus-share專利 US20080035738 - Dynamic credit card with magnetic stripe and embedded encoder and methods for using the same to provide a copy-proof credit card
