CutBackdoor: A Circuit Cut Triggered Backdoor Attack on Variational Quantum Algorithms

CutBackdoor, a novel backdoor attack, exploits the circuit cutting technique used in Variational Quantum Algorithms (VQAs) to compromise their security. By manipulating the circuit cutting process, an attacker can trigger a backdoor in the quantum algorithm, potentially leading to incorrect results or exposing sensitive information. This vulnerability is particularly concerning since VQAs are being developed for applications in quantum chemistry, combinatorial optimization, and quantum machine learning. The attack takes advantage of the fact that real-world VQA deployments often require circuits that exceed available hardware capacity, making circuit cutting a necessary step. Researchers have demonstrated the feasibility of the CutBackdoor attack, highlighting the need for robust security measures in VQA implementations¹. This vulnerability matters to practitioners because it underscores the importance of securing quantum computing systems against novel attack vectors, which can have significant implications for the integrity of quantum computations and the security of sensitive data.