SECURE INTEGRATED CIRCUIT INCLUDING PARTS HAVING A CONFIDENTIAL NATURE AND METHOD FOR OPERATING THE SAME

摘要

The secure integrated circuit (1) further includes storage means (2) in which confidential data is stored, such as an encryption programme and at least an encryption key, and a microprocessor unit (3) for executing the encryption programme. Said circuit further includes an oscillator stage (4, 5) supplying clock 5 signals (CLK) in particular for clocking the sequence of operations in the microprocessor unit (3), and a random number generator (6) connected to the microprocessor unit. A random number (RNGosc) generated by the random number generator is supplied to the input of the oscillator stage to configure it such that the frequency of the clock signals supplied by the oscillator stage depends on said random number. The oscillator stage includes an RC type oscillator, in which a certain number of resistors and/or capacitors can be selected by the random number introduced at the input of the oscillator stage. So the frequency of clock signals depends on the RC component selected as a function of said received random number.