A system and method for isolating a computer system from entry of a personal identification number (PIN) to a smart card. The system and method includes a computer system that is in communication with an unsecure network to allow a user to engage in a purchase transaction. The system and method also includes a smart card reader in which a smart card is inserted and read. A secure personal-identification-number (PIN) entry device is coupled between the computer system and the smart card reader. The secure PIN entry device is used for entering a correct code for the PIN. Communication between computer system and secure PIN entry device is disconnected until the correct code for the PIN is entered at secure PIN entry device and sent to the smart card in order to authorize use of the smart card for the purchase transaction. In response to the correct code for the PIN being entered and sent to the smart card, communication between computer system and secure PIN entry device is established. The secure PIN entry device has a processor for controlling the disconnection and connection of communication between the computer system and the secure PIN entry device. The secure PIN entry device also has a display for displaying a message request relating to the purchase transaction. The message request prompts a user to provide the PIN to authorize use of the smart card for a purchase transaction.