A Thorough Study of State Leakage Mitigation in Quantum Computing with One-Time Pad

Abstract

The ability for users to access quantum computers through the cloud has increased rapidly in recent years. Despite still being Noisy Intermediate-Scale Quantum (NISQ) machines, modern quantum computers are now being actively employed for research and by numerous startups. Quantum algorithms typically produce probabilistic results, necessitating repeated execution to produce the desired outcomes. In order for the execution to begin from the specified ground state each time and for the results of the prior execution not to interfere with the results of the subsequent execution, the reset mechanism must be performed between each iteration to effectively reset the qubits. However, due to noise and errors in quantum computers and specifically these reset mechanisms, a noisy reset operation may lead to systematic errors in the overall computation, as well as potential security and privacy vulnerabilities of information leakage. To counter this issue, we thoroughly examine the state leakage problem in quantum computing, and then propose a solution by employing the classical and quantum one-time pads before the reset mechanism to prevent the state leakage, which works by randomly applying simple gates for each execution of the circuit. In addition, this work explores conditions under which the classical one-time pad, which uses fewer resources, is sufficient to protect state leakage. Finally, we study the role of various errors in state leakage, by evaluating the degrees of leakage under different error levels of gate, measurement, and sampling errors. Our findings offer new perspectives on the design of reset mechanisms and secure quantum computing systems.

Chuanqi Xu

Ph.D. Student

I am a PhD candidate at Yale University. My current research focuses on quantum computing and computer security, where I design novel attacks and defenses targeting quantum computers and quantum cloud providers. Specifically, my work explores security and privacy across the entire technology stack of quantum computers:

1. Investigating vulnerabilities in quantum processors and qubit technologies.
2. Developing secure and private quantum computer systems and architecture.
3. Ensuring the security of quantum algorithms, with a focus on quantum machine learning (QML).

Previously, I worked on RTL design (Verilog) for FPGAs, implementing Post-Quantum Cryptography (PQC) that is secure to both classical and quantum computer attacks.

I am actively seeking roles as a research scientist, software engineer, and quant researcher. I am broadly interested in developing systems and infrastructure, especially for ML/GenAI infrastructure and systems.