Cutting-edge chips, especially those designed to power emerging AI applications, tend to receive the most attention in the media and generate the most excitement. However, so-called “legacy” chips are just as important — if not more — to our daily lives.  

While technological and manufacturing advances in chip-making seek to make chips that are ever-smaller and more powerful, legacy chips are produced using more “mature” process technologies or “nodes,” which roughly describe the size of the features that can be designed into a chip. Larger nodes are associated with older legacy chips, while smaller nodes are associated with newer, more cutting-edge chips. Legacy chips can be found in a wide variety of products including vehicles, aircraft, appliances, military systems and medical devices, among others.

Despite garnering less attention than their more cutting-edge cousins, legacy chips have been in the news recently. The Biden administration launched an investigation into China’s production of legacy chips, which they are able to manufacture at scale. According to Secretary of Commerce Gina Raimondo, around two-thirds of U.S. products contain legacy chips from China. The investigation will also research the extent to which legacy chips are used within products for critical industries, including applications like defense, healthcare, aerospace, communications and energy systems. 

However, with the Biden administration in its final days, the investigation into legacy chips will soon be handed off to the incoming Trump administration. While it is uncertain what the new administration will do with the investigation, the need for secure and resilient supply chains will remain an ongoing national priority. Recent bans by China on exports of various chipmaking materials to the U.S. highlight the role that chips, and the complex supply chains that enable their production, play on the international stage.  

A steady and secure source of legacy chips is important for the security of the systems they enable, and by extension, the nation. The boundaries between the cyber and physical worlds continue to blur, and many products that we use and depend on are now a mixture between physical and cyber systems. Such “cyber-physical systems” include things like vehicles, industrial control systems and energy grids. 

Legacy chips are important for these systems for at least two reasons. The first is simply that it is necessary to have enough supply to meet the demand. The global economy experienced chip shortages during and after the COVID lockdowns. Due to the shortage of chips needed for cars, for example, it is estimated that the auto industry lost hundreds of billions of dollars by not producing around 11 million vehicles that otherwise would have been manufactured if there were enough chips. Without an adequate supply of chips, companies won’t be able to produce all of the things that people want to buy. 

Second, having a trusted supply of legacy chips is important because the security of the systems they enable depends on the security of the chips themselves. Vulnerabilities in the hardware can allow attackers to disable these critical systems and steal data. Counterfeits can also enter the supply chain that have degraded quality and reliability. While software can be patched, it is much more difficult to update hardware. Security at the physical, hardware layer is important for ensuring the security of the system as a whole. 

On the bright side, according to the Semiconductor Industry Association, multiple awards announced under the CHIPS and Science Act include mature-node technology. Moving forward, strengthening the nation’s electronics ecosystem will require continued growth of the entire spectrum of chips, from legacy to cutting-edge. It will also require strengthening domestic capacity for supporting technologies, such as printed circuit boards, and the acquisition of raw materials like quartz, gallium and germanium. End-to-end traceability can help supply chain managers gain visibility into where components have been and where they are going. For older components, proactive obsolescence management policies can help to ensure that enough inventory is in place before the components are no longer manufactured.  

As demand for connected devices and digital technologies continues to increase, so does the need for trusted and secure chips. Legacy chips are one important piece of that puzzle. Strengthening the domestic supply chain for legacy chips reduces security vulnerabilities and promotes economic resilience. 

Zachary A. Collier, Ph.D., is an assistant professor of management at Radford University. He is a visiting scholar at the Center for Hardware and Embedded Systems Security and Trust.