Synopsis: Rapid-Fire Random Bits

Tests show that an all-electronic system can generate 80 billion random bits per second.

Encrypted communications and other technologies require billions of random bits per second, but generating them in software isn’t truly random. Chaotic laser signals can also produce randomness, but now Wen Li, of the Chinese Academy of Sciences in Suzhou, and her colleagues report in Physical Review Letters a simpler, all-electronic system that might someday become a “random bit chip.” It uses chaotic currents in a superlattice to generate 80 billion random bits per second.

The superlattice used by the team was like a multilayered semiconductor sandwich that presented vertically traveling electrons with two sequential barriers. Such a structure leads to plateaus in the current-voltage curve. Fixing the voltage at one of these plateaus can produce a current that spikes at random intervals, roughly every 5 nanoseconds. Last year Li and colleagues reported that the amplitude of this current might be suitable for rapid random bit generation.

Now Li and her Chinese colleagues along with collaborators from Bar-Ilan University in Israel have put this superlattice through its paces, using two different signal processing techniques to increase the “bumpiness” of the current signal between spikes. With a more rapidly varying signal, the team could generate a higher rate of random bits. The first technique involved taking multiple derivatives; the second involved combining several sections of the signal from different times. In each case, the team saved only the last four or five “least significant” bits of each point sampled from the amplitude to add to the random bit stream and then verified the randomness with statistical tests. They say either technique or a combination may be appropriate, depending on experimental requirements. – David Ehrenstein


Features

More Features »

Announcements

More Announcements »

Subject Areas

Semiconductor PhysicsNonlinear DynamicsElectronics

Previous Synopsis

Quantum Information

Quieter Quantum Amplifiers

Read More »

Next Synopsis

Related Articles

Synopsis: Mimicking the Brain with Superconductors and LEDs
Optoelectronics

Synopsis: Mimicking the Brain with Superconductors and LEDs

A proposed computer made of superconductors communicating via light could carry out more operations than a human brain while using less energy.   Read More »

Viewpoint: Searching for Order in Turbulent Flow
Fluid Dynamics

Viewpoint: Searching for Order in Turbulent Flow

The observation of ordered flow patterns in a weakly turbulent liquid may lead to new ways of predicting the evolution of turbulent flow. Read More »

Synopsis: Straining After Quantum Dots
Semiconductor Physics

Synopsis: Straining After Quantum Dots

The positions of quantum dots inside a microstructure can be determined by monitoring how an applied strain affects the dots’ photoluminescence.   Read More »

More Articles