  The emergence of noisy intermediate-scale quantum (NISQ) computers has
important consequences for cryptographic algorithms. It is theoretically
well-established that key algorithms used in cybersecurity are vulnerable to
quantum computers due to the fact that theoretical security guarantees,
designed based on algorithmic complexity for classical computers, are not
sufficient for quantum circuits. Many different quantum algorithms have been
developed, which have potentially broad applications on future computing
systems. However, this potential depends on the continued maturation of quantum
hardware, which remains an area of active research and development. Theoretical
limits provide an upper bound on the performance for algorithms. In practice,
threats to encryption can only be accurately be assessed in the context of the
rapidly evolving hardware and software landscape. Software co-design refers to
the concurrent design of software and hardware as a way to understand the
limitations of current capabilities and develop effective strategies to advance
the state of the art. Since the capabilities for classical computation
currently exceed quantum capabilities, quantum emulation techniques can play an
important role in the co-design process. In this paper, we describe how the
{\em cuQuantum} environment can support quantum algorithm co-design activities
using widely-available commodity hardware. We describe how emulation techniques
can be used to assess the impact of noise on algorithms of interest, and
identify limitations associated with current hardware. We present our analysis
in the context of areas of priority for cybersecurity and cryptography in
particular since these algorithms are extraordinarily consequential for
securing information in the digital world.
