Abstract: A secure card reader (1) includes several security measures. Access to the reader's main circuitry is prevented by an enclosure (9) whose walls contain embedded i conductive paths (18a, 18b, 18c). Breaking or grounding of one of these paths can be detected electronically. A similar arrangement of conductive paths prevent enlarging of a card receiving slot (9c) If tampering is detected using the embedded conductive paths (18a, 18b, 18c), the reader's memory (69) is wiped. The enclosure (9) has apertures (20) in its walls and is held in place by a potting material that extends into the apertures. Means (31, 35) is also provided to detect attempts to probe behind a keypad membrane (7). The contacts (42) for the chip of a chip card are arranged so that their leads all extend away from the card insertion slot.