TECHNICAL FIELD

Generally, a merchant uses a point-of-sale terminal to process a transaction. The terminal is connected, usually with wires, to a cash register and to an Internet connection. Some terminals process chip cards; for such terminals, a card is inserted into the terminal and the user enters a Personal Identification Number (PIN) on a keypad of the terminal. Other terminals process magnetic stripe cards. For such terminals, the card is swiped through a slot. Mobile card readers are also available for magnetic stripe cards.

Some mobile card readers, e.g., in taxies, use cellular technology to communicate wirelessly with the credit card processor. Some mobile card readers use wireless technology, e.g., Bluetooth®, to communicate with the credit card processor. Bluetooth uses a process called pairing to allow devices to communicate with each other. Pairing mechanisms include legacy pairing and Secure Simple Pairing (SSP). SSP includes a number of association models for pairing, namely, “just works”, “numeric comparison”, “passkey entry”, and “out of band (OOB),” specifically designed to counter a “Man-In-The-Middle Attack” (MITM) exploit. MITM is an attack by a rogue device, which attempts to insinuate itself into the legitimate Bluetooth “trust dialogue” during pairing.

