A touch sensor is configured to sense a contact event occurring between a body part of a user and the touch sensor. The touch sensor is configured to produce contact data in response to the sensed contact event. A processor is coupled to the touch sensor and memory. The processor is configured to store in the memory a sequence of data frames each comprising contact data associated with a different portion of the user's body part. The processor is further configured to generate biometric signature data using the sequence of data frames.
