Key for High Security in Future Ubiquitous Mobile Commerce Society

TOKYO--Toshiba Corporation today announced development of an ultra-compact real random number generator (RNG) that is dramatically smaller and more power efficient than other real RNG, and that can be used in small mobile equipment that transmits and receives encrypted information.

Hacker-proof encryption is essential for e-commerce and secure information exchanges. The most effective encryption algorithms rely on random numbers, and on a high quality random number generator that assures non-periodicity and non-reproduction of the numbers generated. However, real random number generators, which rely on random physical phenomenon, are so large and consume so much power that their use has been limited to large-sized computers and PCs. Mobile terminals have had to rely on pseudo-RNG, which require additional circuitry to assure the quality of random number generation. Such circuitry impedes miniaturization.

Toshiba developed its ultra-compact real RNG through development of a nano-scale structure that uses the phenomenon of the characteristic appearance of a single electron in a semi-stable location. In practical terms, this achieves a real RNG that is only one hundred millionth of the size of conventional real RNG. Reduced size is complemented by a significant reduction in power consumption, to a level of only one ten millionth that of other real RNG.

Full details of the RNG will be presented in a Highlight Paper at the December 9-11 International Electron Devices Meeting (IEDM) in San Francisco.

Toshiba’s random number generator

In Toshiba’s new RNG, a single electron enters and exits a semi-stable location, and its passage provides a random source of physical phenomena. A single electron transistor that is extremely sensitive to electric charges detects the movement of the electron, and it can extract a fairly large output signal without any need of a complicated circuit. The ability of the random number generator to use the appearance and disappearance of the electron allows generation of very high quality random numbers.

Toshiba fabricated the nanometer-scale dots necessary for the semi-stable location by treating a 2.5 nanometer thick silicon surface with alkaline-based solutions. The result is a nanometer-scale alpine landscape, with the peaks providing the desired dots. Experiments with ultra-thin silicon on an insulator confirmed the ability to achieve a cluster of dots, and this was used to fabricate single-electron transistors that can operate at room temperature.

The new RNG circuit is shrunk down to one square micron (1 micron x 1 micron), approximately 1/100,000,000 that of current real physical phenomenon RNG. Power consumption is 1.5nanowatt, approximately 1/10,000,000 of that of current high-quality real physical phenomenon RNG.

Note: The single electron device technology employed in this RNG was developed in part as consigned research under a NEDO National Project, Quantum Function Device. Research on the RNG was undertaken as consigned research from the Telecommunications Advancement Organization of Japan.