A high-speed oscillator-based truly random number source for cryptographic applications on a smartcard IC

Abstract

The design of a high-speed IC random number source macro-cell, suitable to be integrated in a Smart Card microcontroller, is presented. The oscillator sampling technique is exploited and a jittered oscillator which features an amplified thermal noise source has been designed in order to increase the output throughput and the statistical quality of the generated bit sequences. The oscillator feedback loop acts as an offset compensation for the noise amplifier, thus solving one of the major issues in this kind of circuit. A numerical model for the proposed system has been developed which allows us to carry out an analytical expression for the transition probability between successive bits in the output stream. A prototype chip has been fabricated in a standard digital 0:18"m n-well CMOS process which features a 10Mbps throughput and fulfills the NIST FIPS and correlation-based tests for randomness. The macro-cell area, excluding pads, is 0:0016mm 2 (184"m  86"m) and a 2:3mW power consumption has been measured.

A Robust Chaos-Based True Random Number Generator Embedded in Reconfigurable Switched-Capacitor Hardware

“…Currently the most frequently used phenomenon in embedded TRNGs is direct noise amplification of a resistor [3] and jitter noise of digital clock signals [4]. Embedded TRNGs frequently use some external devices or rather heuristic source of randomness (e.g.…”

Random numbers from an integrated CMOS double-scroll

“…For example, a clocked comparator can generate '0', '1' digital bits. The time-to-digit converter (TDC) method [3] and the oscillator sampling method [2] can also deal with a chaotic signal. However, the above methods can't make full use of the statistics of a chaotic signal which are more stable and controllable than those of noises.…”

“…One intuitive method is to amplify and sample devices' noises such as thermal noise [1], but its disadvantage is that the circuits are usually unable to shield noises from supply and substrate. Some papers employ the oscillator sampling method [2] or the meta-stability method [3], but the randomness in these generators is also brought by devices' noises.…”

Design of Testable Random Bit Generators

“…A first example of stateless noise source can be obtained from the well-know oscillator-based random bit generator [8,9,10,11] if both oscillators are stopped after each bit generation (Figure 3), thus avoiding the phase shifting between f fast and f slow . If digital ring oscillators are employed to implement f fast and f slow , the start-up time is usually a small fraction of the their oscillating period.…”