The MIFARE Classic® by NXP is the most recognized and widely used contactless smart card in the market. Its design and implementation details are kept secret by its manufacturer. This paper studies the architecture of the card and the communication protocol between card and card reader. Then it gives a practical, low-cost, attack that recovers secret information from the memory of the card.
MIFARE Classic ICs operating in the 13.56 MHZ frequency range with read/write capability and ISO 14443 compliance.