"An Ionic Black Box"

This illustration from CE Prof. Dmitri Strukov is of a memristor as a cybersecurity device that appeared on the cover of Nature Electronics (The UCSB Current)

Memristor cybersecurity illustration

UCSB researchers use emerging memory devices to develop electronic circuits for cybersecurity applications

While we embrace the way the Internet of Things already is making our lives more streamlined and convenient, the cybersecurity risk posed by millions of wirelessly connected gadgets, devices and appliances remains a huge concern. Even single, targeted attacks can result in major damage; when cybercriminals control and manipulate several nodes in a network, the potential for destruction increases.

UC Santa Barbara computer science professor Dmitri Strukov is working to address the latter. He and his team are looking to put an extra layer of security on the growing number of internet- and Bluetooth-enabled devices with technology that aims to prevent cloning, the practice by which nodes in a network are replicated and then used to launch attacks from within the network. A chip that deploys ionic memristor technology, it is an analog memory hardware solution to a digital problem.

“You can think of it as a black box,” said Strukov, whose new paper, “Hardware-intrinsic security primitives enabled by analogue state and nonlinear conductance variations in integrated memristors,” appears on the cover of Nature Electronics. Due to its nature, the chip is physically unclonable and can thus render the device invulnerable to hijacking, counterfeiting or replication by cyber criminals.

Key to this technology is the memristor, or memory resistor — an electrical resistance switch that can “remember” its state of resistance based on its history of applied voltage and current. Not only can memristors can change their outputs in response to their histories, but each memristor, due to the physical structure of its material, also is unique in its response to applied voltage and current. Therefore, a circuit made of memristors results in a black box of sorts, as Strukov called it, with outputs extremely difficult to predict based on the inputs.

“The idea is that it’s hard to predict, and because it’s hard to predict, it’s hard to reproduce,” Strukov said. The multitude of possible inputs can result in at least as many outputs — the more memristors, the more possibilities. Running each would take more time than an attacker may reasonably have to clone one device, let alone a network of them.