Many companies plan to use quantum-cryptographic infrastructure or aim to become quantum-safe. For the overall system to achieve the desired security level it is, however, not sufficient to simply use a quantum-cryptographic device. They need to be part of the complete security concept and security architecture. We develop concepts and protocols for IT-systems which involve quantum cryptography or are designed to withstand attacks with quantum computers. For existing proposals, we also provide security analysis and reviews.
Quantum Key Distribution creates secure keys from quantum-physical processes. The data obtained from physical measurements, however, is never perfect. It has to be further processed to condense partially secure raw keys into highly secure keys which can be used in applications. The classical algorithms used in this context are called “privacy amplification” and are usually built-in in quantum-cryptographic devices. The correct working of this component is crucial for the security of the complete key.
We have built reference implementations of commonly used algorithms and set up a testing infrastructure to verify the correct working of privacy amplification.
Quantum Random Number Generators can be used in entropy pools or to generate secure keys locally. We have set up a quantum random number generator device and built applications drawing their random numbers from this device, e.g. in encryption, simulation and as randomness beacon.
The systems developed for these applications allow to integrate quantum random number generators in commercial IT systems and evaluate the use of quantum random number generator hardware in different environments.
A variety of classical algorithms for public key cryptography are currently being proposed to withstand attacks using quantum computers. While these post-quantum algorithms can run on traditional hardware, they differ in key size, speed (for key generation, signing and/or verifying, etc.) and memory requirements. These differences can impact applications.
We have set up a benchmarking infrastructure to evaluate the use of these algorithms in different contexts, focusing in particular on the signature algorithms.
Quantum computers can be accessed over the cloud. Simply using a quantum computer does, however, not bring any advantage. To make use of the quantum computer’s potential, software needs to be adapted and tailored to specific applications and to the current noisy quantum hardware. For some use cases, quantum computers may be useful, while for others they may not be suitable. We study the usefulness of quantum computers in the context of practical applications and develop and implement the corresponding algorithms, as well as testing them on currently accessible quantum hardware.
