Hiding information transmitted on a data bus

摘要

A smart card is provided in which non-encrypted data on the data bus, in particular address data, is hidden. The smart card comprises a microcontroller (10), a memory (12) and a data bus (14) for the transmission of data therebetween. Memory address data is hidden by use of a data bus interface (18) provided at each of the microcontroller (10) and the memory (12) which performs a scrambling/unscrambling function on the non-encrypted data.