Anti-hacking based on the circular polarization direction of light

November 06, 2020

The Internet of Things (IoT) allowing smart phones, home appliances, drones and self-driving vehicles to exchange digital information in real time requires a powerful security solution, as it can have a direct impact on user safety and assets. A solution for IoT security that has been is a physical unclonable function (PUF) that can supplement software-based key security vulnerable to various attack or physical attack.

Hardware-based PUF semiconductor chips, for example, each have a unique physical code, similar to the human iris and fingerprints. Because the variations in the microstructure derived from manufacturing process act as a key value, the security keys generated via PUFs are random and unique, making it impossible to duplicate. However, there were limitations in that the hardware structure had to be changed in order to increase the number of combinations of keys to enhance cryptographic characteristics.

Under these circumstances, a team led by Jung-Ah Lim and Hyunsu Ju from the Korea Institute of Science and Technology (KIST) Center for Opto-Electronic Materials and Devices announced that they have successfully developed an encryption device that can greatly strengthen the cryptographic characteristics of PUFs selectively detecting circular polarization, without modify the hardware structure, through collaboration with a team headed by Suk-Kyun Ahn, Professor of Polymer Science and Engineering at Pusan National University.

Light, which behaves as both a particle and a wave, can travel in a straight line, while rotating in the form of a spiral, as circularly polarized light.

The core technology applied to the encryption device developed by the KIST and PNU research team is a phototransistor that can detect the circular polarization of light rotating in a clockwise or counterclockwise direction.

The main strategy used in the newly developed photoresistor is a combination of cholesteric liquid crystal and low bandgap π-conjugated polymer with excellent near-infrared light absorption and charge transport properties. The cholesteric liquid crystal film has a strong tendency to selectively reflect near-infrared circularly polarized light, as the amount of light reaching the device is controlled according to the rotational direction of the light. In the study, the device exhibited excellent dissymmetry factor for photocurrent with high sensitivity in detecting circularly polarized light.

The research team succeeded in fabricating a PUF device that could serve as a fundamental solution against hacking, wiretapping, etc. by increasing the number of combinations in generating encryption keys using a simple solution process, without changing the physical size of the array.

Dr. Jung-Ah Lim from KIST said, "This study presents measures to implement a new encryption device amidst the need to develop a highly secure cryptographic technology with the advent of the era of IoT.

Dr. Suk-Kyun Ahn from PNU said, "The technology to discriminate the rotational direction of circularly polaized light based on a simple fabrication process is expected to have a strong potential in not only next-generation encryption devices but also dvarious chiroptical optoelectronic applications."
Glossary description:
* Circularly polarized light: Light that travels in a straight line while rotating in either a clockwise or a counterclockwise direction
* Phototransistor: A device that can perform signal amplification and act as a switch by detecting basic characteristics (wavelength, intensity, etc.) of light along with current/voltage

es to editors:
This study was carried out with a grant from the Ministry of Science and ICT (MSIT), as part of the Institutional R&D Program of KIST, and Material Convergence and Innovative Technology Development Program. The findings were reported in the latest edition of the international journal, Advanced Functional Materials
(IF: 16.836, Top 4.678% in the field of JCR).

National Research Council of Science & Technology

Related Technology Articles from Brightsurf:

December issue SLAS Technology features 'advances in technology to address COVID-19'
The December issue of SLAS Technology is a special collection featuring the cover article, ''Advances in Technology to Address COVID-19'' by editors Edward Kai-Hua Chow, Ph.D., (National University of Singapore), Pak Kin Wong, Ph.D., (The Pennsylvania State University, PA, USA) and Xianting Ding, Ph.D., (Shanghai Jiao Tong University, Shanghai, China).

October issue SLAS Technology now available
The October issue of SLAS Technology features the cover article, 'Role of Digital Microfl-uidics in Enabling Access to Laboratory Automation and Making Biology Programmable' by Varun B.

Robot technology for everyone or only for the average person?
Robot technology is being used more and more in health rehabilitation and in working life.

Novel biomarker technology for cancer diagnostics
A new way of identifying cancer biomarkers has been developed by researchers at Lund University in Sweden.

Technology innovation for neurology
TU Graz researcher Francesco Greco has developed ultra-light tattoo electrodes that are hardly noticeable on the skin and make long-term measurements of brain activity cheaper and easier.

April's SLAS Technology is now available
April's Edition of SLAS Technology Features Cover Article, 'CURATE.AI: Optimizing Personalized Medicine with Artificial Intelligence'.

Technology in higher education: learning with it instead of from it
Technology has shifted the way that professors teach students in higher education.

Post-lithium technology
Next-generation batteries will probably see the replacement of lithium ions by more abundant and environmentally benign alkali metal or multivalent ions.

Rethinking the role of technology in the classroom
Introducing tablets and laptops to the classroom has certain educational virtues, according to Annahita Ball, an assistant professor in the University at Buffalo School of Social Work, but her research suggests that tech has its limitations as well.

The science and technology of FAST
The Five hundred-meter Aperture Spherical radio Telescope (FAST), located in a radio quiet zone, with the targets (e.g., radio pulsars and neutron stars, galactic and extragalactic 21-cm HI emission).

Read More: Technology News and Technology Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to