Protecting semiconductors with wafer-level packaging

Microelectronics have long become a ubiquitous feature of life, and with novel applications like self-driving cars just around the corner, they will become an even more important part of the fabric of modern society. Their ability to fit in and navigate the human world is made possible by ever more sophisticated radar technology. But the manufacturing of these highly complex systems is prone to certain risks and threads, not least among them the ever-present danger of criminal manipulation: Systems can be tampered with or corrupted by replacing individual components. The researchers at Fraunhofer IZM have made it their mission to prevent such critical manipulations by developing trustworthy systems with wafer-level packaging (WLP). The technology is already the standard packaging approach for mobile devices like smartphones, and it makes it possible to stay in control of every single component of the system.

The REWAL project was set up to take the WLP technology to the next level by equipping it with a trust architecture that shields highly integrated components like chiplets from manipulation. The researchers also hope to create the technological basis for new platform solutions for the trustworthy heterogeneous systems of the future.

The approach works by obfuscating the functions of the system through partitioning: In so-called split manufacturing, different components are made by different producers, individual algorithms are spread out among them, and the application code is changed to prevent illicit access and tampering with the individual pieces. Additional smart cards are inserted with the different components to encrypt the data shared between them.

At Fraunhofer IZM, wafer-level packaging is currently being used to produce a modular MIMO radar system for autonomous vehicles. To ensure the trustworthiness of a sensitive product of this nature, special built-in self-tests are included as secure elements. The researchers and developers are also using encrypted connections between the chiplets of the system to hide the sensitive information and make it impossible for would-be attackers to manipulate the hardware.

Partners on the project: Conti Temic microelectronic GmbH, Infineon Technologies AG, Viconnis Test Technologie GmbH, Ruhr University of Bochum, Technical University of Ingolstadt, University of Bremen, Fraunhofer IZM

Multisensor shielding for electronic systems

Be it banking, sensitive business information, or just private communication – confidential or even secret data is constantly flowing through electronic channels. But every electronic circuit has its weak spots that allow the communication to be listened in on and information to be stolen. These can include tiny fluctuations in power usage, electromagnetic fields, open interfaces, or the data transmission process itself. The question is: How can these potential leaks be found and plugged? Can electronic devices learn to recognize and beat off potential attacks? And how can authorization processes be made secure? Finding answers is the job of the team of the VE-SAFE project, which is looking into the potential of multi-sensor solutions to fight attacks on electronic systems.

Intensive research into the potential weak spots of electronics is leading the researchers into new avenues for protection on the module level: A hierarchy of multiple sensor systems can be used to put in place a security concept that can detect attempted manipulation and take the necessary countermeasures. New opportunities in assembly and packaging technologies are combined with non-destructive testing mechanisms to check the integrity of the protections. If the system detects manipulation, a special guardian switch initiates the necessary measures to protect the system.

The team of the sub-project is working on a multi-modular demonstrator unit that integrates the complete monitoring system with the client’s actual electronics, with Fraunhofer IZM contributing the design, production, and testing of the essential sensors.

Partners on the project: HTV Halbleiter-Test & Vertriebs-GmbH, Jenaer Leiterplatten GmbH, Fraunhofer IZM

How photonics prevents wiretapping

The Silhouette project brings together the bright research minds of the consortium in a mission to make open procedural systems more trustworthy with silicon-based photonic technology. Photonics uses light to transmit information, making it harder to manipulate and virtually preventing eavesdropping. It is not only an ideal choice for sensitive communication channels; the many benefits of silicon-based photonics include faster processing and less energy consumption – important qualities for the Internet of Things.

The key aim of the project is to build a standardized modular platform that can be used to translate electrical into optical signals, process and validate them, and revert them back into electrical signals at the other end. This process is the job of an electro-optical interposer whose design and process technology is being developed in the project. The new interposer will benefit from the fact that it can be readily combined with existing data security hardware for a powerful hybrid system.

For Silhouette, two demonstration units will be created to showcase different approaches for trustworthy electronics. A random number generator is included in one of these two E/O platforms, where its output is used to create the digital keys needed for truly secure encrypted communication. The other platform will have the keys generated directly in the photonic domain and then go through the electrical-optical transition.

Partners on the project: Fraunhofer IPMS, Fraunhofer HHI, Fraunhofer IAVT, Fraunhofer IZM-ASSID and TU Dresden, OSRAM Opto Semiconductors GmbH, and qutools GmbH.

Thinking holistically: The Velektronik platform

It is not just the industrial world that will benefit from secure and trustworthy electronics. Medical applications and the consumer market will also become increasingly reliant on it, as tampering and unauthorized access by third parties can have a direct and potentially dangerous effect on the patient or end user. This is why the researchers on the Velektronik project are taking the entire value chain in their sights, with a focus on three of its most important links: Design, electronics manufacturing, and value chain analysis.

In addition to producing an overview of current technology and pinpointing potential for standardization, the researchers are looking for concrete solutions to pursue, such as ways to protect the IP of individual components or to harden the interfaces between software and hardware.

The results of the Velektronik efforts will feed into a platform coordinated by the Research Fab Microelectronics Germany, from where they can be accessed in science and business. Their practical relevance is ensured by a representative advisory council of industry partners. The expected progress is assumed to promote the digital sovereignty of Germany’s and Europe’s industry, offering important benefits not least for small to medium-sized enterprises.

Partners on the project: Fraunhofer Institutes AISEC, EMFT, IAF, IIS, IMS, IMWS, IPMS, ISIT, ENAS, IZM and the FMD as well as the Leibniz Institutes FBH and IHP and the edacentrum GmbH, Hannover.

All four projects that Fraunhofer IZM is actively contributing to are supported with a total of EUR 25.45 million in funding from the Federal Ministry of Education and Research as part of the ZEUS Trustworthy Electronics research campaign.