Hardware Security

Attacks

Side-channel attacks

Side-channel attacks are fundamentally different from conventional attacks on cryptographic algorithms. In the latter case, attackers attempt to solve a complex mathematical problem or search the entire key space to break cryptographic systems.  In contrast, side-channel attacks use information such as runtime, power consumption, or electromagnetic emission. Attackers can use this information to obtain secret data stored on the device. We evaluate the side-channel security of cryptographic implementations in our hardware lab using state-of-the-art high-precision measurement equipment and software. The knowledge generated there is used to design and implement countermeasures which are customized for a specific target platform.

Fault attacks

Fault attacks attempt to disrupt systems in a specific way. This can be accomplished by increasing or decreasing the supply voltage, by changing the frequency or the ambient temperature, or by deliberately disturbing the system using lasers or electromagnetic pulses. Combined with knowledge of the operating principle of a cryptographic algorithm, the intentionally induced errors can be used to gather information about the secret key processed internally. Likewise, it can be utilized to bypass memory protection measures or to activate debug interfaces. Laser-assisted error injection makes it possible to induce errors with very high accuracy (in terms of time and location). This gives the attacker more control and allows a wider range of attacks. Our hardware lab has two different laser stations to perform fault attacks and evaluate device security and countermeasures.

Machine Learning

Modern statistical methods, which are often summarized under the term machine learning, serve to improve the evaluation of complex data. Machine learning offers the necessary flexibility to make complex statistical correlations visible. In the Hardware Security department, various algorithms are used to evaluate measurement data from side-channel measurements and for anomaly detection in sensor networks. Machine learning not only helps to better understand sensor data on resource-constrained platforms or side-channel measurements with terabytes of data, but also opens up the application to a variety of new kinds of problems.

Internet-of-Things

Systems in the Internet-of-Things (IoT) typically have a long operating time, limited processing resources and a reduced battery life. In the process, they may also incur only low costs in production and operation. Due to these constraints, many of the established security technologies cannot be directly transferred to the IoT domain. One research focus of the department Hardware Security therefore lies on innovative hardware and software design patterns that aim to increase the resilience of IoT devices with limited resources against cyber attacks. These include, for example, memory protection mechanisms, system attestation and identities, and measures against denial-of-service attacks.

Medical Devices

Connected medical devices and so-called wearables, such as continuous glucose monitors or implanted pacemakers, are exposed to high risks of attack due to their increasing distribution and functionality. Based on our analysis and solution expertise from hardware to networks security, we help manufacturers to design secure devices that also meet the requirements of the new Medical Device Regulation (MDR).

Sensor Networks

Wireless sensor networks are the sensory organs of the Internet-of-Things. Often, the collected data is critical and must be protected against eavesdropping or manipulation. The management of the cryptographic keys required for this purpose is challenging due to the large number of sensor nodes and their limited computing power. We are therefore continuously expanding our expertise in the field of key management solutions that combine security and user-friendliness and enable any user to easily operate secure wireless sensor networks.

System-on-Chips

Systems-on-chips (SoCs) combine a multitude of functions in a single chip. They are the foundation of countless embedded systems and must therefore be protected carefully. The many functions of an SoC provide a large surface for attack, which makes securing them a major challenge. Debug interfaces and external memory modules must be secured, cryptographic keys must be stored in a secure manner, and software must be executed securely. Secure boot and update, firmware encryption, key storage, protection of intellectual property and secure execution environments are just some of the topics that have been the focus of the Hardware Security department for years.

Tamper Protection

Embedded systems are exposed to physical tampering to manipulate the system or derive critical secrets, especially in the domain of high-assurance communication. Detecting and reacting to tampering requires the interaction of sensor technologies, electronics and embedded security. We are collaborating with technology partners to design new tamper protection methods, in particular based on Physical Unclonable Function (PUFs) to assess the physical integrity of a device based on the validity of a physical hardware fingerprint.

FPGAs und PUFs

The use of programmable hardware, so-called Field Programmable Gate Arrays (FPGAs), in embedded systems and as part of high-performance systems-on-chip is growing rapidly. In this context, purchased third-party designs can compromise the security of the overall system from the inside. Our security reviews identify specific points of attack and help to secure systems at an early stage. Another research area deals with the use of FPGAs as a basis for Physical Unclonable Functions (PUFs). PUFs are circuits that use manufacturing variations to create a unique bit string. This can then be used to bind cryptographic keys or uniquely identify a chip. PUFs can be used in FPGA applications to provide the user with a secure key store without relying on security features provided by the manufacturer. These are often less trustworthy and more vulnerable to attack. Here, an array of over 200 FPGAs allows us to analyze the statistical properties of improved and novel implementations of PUF circuits on FPGAs.

Trusted Electronics

Securing electronics supply chains and the topic of secure open-source hardware, especially RISC-V based system-on-chips, have become more important in recent years. We use our competencies in electronics security here and research RISC-V based designs and hardened crypto accelerators, as well as improved test methods for evaluating trustworthiness.