Spanish and Italian engineers have built a quantum number generator for encryption that’s small enough to be integrated in a mobile device.
The researchers used photonic integrated circuits (PICs) to create two random number generators. The work, which was reported in the Optical Society's journal Optica, represents a key advance for incorporating quantum encryption into computers, tablets and mobile phones.
The new device operates at speeds in the range of gigabits per second, fast enough for real-time encryption of communication data, such as a telephone or video calls, or for encrypting large amounts of data travelling to and from a server, such as that from social media platforms. It could also find use in stock market predictions and complex scientific simulations of random processes, such as biological interactions or nuclear reactions.
‘We’ve managed to put quantum-based technology that has been used in high profile science experiments into a package that might allow it to be used commercially,’ said the paper’s first author, Carlos Abellan, a doctoral student at ICFO-The Institute of Photonic Sciences in Barcelona, Spain. ‘This is likely just one example of quantum technologies that will soon be available for use in real commercial products. It is a big step forward as far as integration is concerned.’
The device generates random numbers based on the quantum properties of light, a process that is inherently random and thus impossible to predict no matter how much information is known.
Several research groups are working to develop simpler, smaller ion traps for quantum computing. Researchers at MIT recently described a prototype chip that can trap ions in an electric field and, with built-in optics, direct laser light towards each of them. The chip, described in Nature Nanotechnology, decreases the size and complexity of the equipment required to trap ions, which in turn act as quantum bits, the core elements used in quantum computing.
Valerio Pruneri at ICFO, who led the collaborative research effort to build the random number generator, said: ‘In this paper, we made a huge technological advance by using a new design that includes two lasers that interfere with each other in a confined space. This makes the device smaller while keeping the same properties that were used in past experiments.’
Photonic integrated circuits offer a way to integrate photonic components — such as the lasers and detectors used by the new quantum random generator — onto a chip with a small footprint and low power consumption. PIC-based devices can be integrated with traditional electronics, which could allow the random number generator to be used for driving, reading and processing electronics necessary for computation or communications.
‘We proved that quantum technologies are within practical reach by exploiting PICs,’ said Pruneri. ‘Quantum random number generation as well as quantum cryptography and other quantum-based technologies will benefit from PIC-based technology because it allows one to build commercial and innovative products. Ours is a first demonstration.’