Techniques are described for performing secure card not present (CNP) transactions using integrated circuit chip-enabled cards. The techniques include continually or periodically tracking a location of a user's card by a user computing device, e.g., a “smart” phone, and storing a log of datasets relating to the location of the user's card at a server device. Based on the tracking, the user computing device may alert the user via a push notification or other message when the user's card is not within a preset range of the user computing device. In addition, an authentication server determines a location of a purchaser computing device attempting to perform a CNP transaction using the user's card information, and compares the location of the purchaser computing device with a most recent location of the user's card retrieved from the log of datasets to determine whether to approve the CNP transaction.