Toshiba has announced the development of an advance in information security technology: A physical random-number generation circuit that achieves high output by area, and that generates random numbers at a data rate of 2.0 megabits a second. The newly developed random-number generator (RNG) has a circuit size of 1,200 square micrometers and achieves the level of performance and reliability essential for integration into IC cards and mobile equipment.
The new RNG technology adopts a compact analogue/digital (A/D) converter which amplifies analogue noise signals and converts them to digital random numbers. The technology also integrates a Toshiba-developed compact noise source device. This generates the noise signal by using stochastic physical phenomenon of electrons trapped in the silicon nitride (SiN) layer of a transistor; the layer traps and releases high density electrons at a high generation rate. This RNG circuit is also not subject to temperature dependence.
This work is supported in part by the National Institute of Information and Communications Technology (NICT) of Japan. Toshiba's new physical RNG circuit relies on a nanometer-scale noise source device that is not affected by temperature. This device generates large noise signals at high frequency. The newly developed circuit digitizes these large, high frequency signals.
The new technology employs a filter and differential amplifier with a comparator, which is separated from the noise source device. It can selectively extract the high frequency noise signals generated by the new device and can achieve a high random number generation. The improved circuit downsizes the A/D converter. The generated numbers using this circuit are not affected by temperature, verifying the possibility of stable generation of random numbers under the temperature conditions in which IC cards and mobile equipment are used.
