There is a steady growth in research and demand for real quan- tum hardware in the Noisy Intermediate-Scale Quantum (NISQ) era of quantum computing. This prompts many third-party cloud providers to set up quantum hardware as a service that includes a wide range of qubit technologies and architectures to maximize performance at minimal cost. Quantum circuits submitted to these services are the fruits of the efforts invested by the designers. But these third-party cloud compilers (who offer more efficient alter- natives to established compilers) can make user circuits/programs vulnerable to various security breaches. Communication channels for transmitting quantum information also need to be developed such that there is end to end encryption. There is little to no visibil- ity on where the execution of the circuit is actually taking place. The success of the user program is highly reliant on the backend that was used for execution. Besides, the third-party provider and/or tools (e.g., hardware mapper and allocator) may be untrustworthy and execute the quantum circuits on less efficient and more error- prone hardware to conserve resources and maximize profit. These vulnerabilities in the quantum system could leak confidential data, cause loss of intellectual property rights of designers, cause loss of access control, corrupt user programs et cetera. Thus, it is imper- ative to identify these security vulnerabilities and create defense strategies to protect quantum programs, thus helping to maintain the integrity of quantum information across the software stack. My thesis aims to help address these vulnerabilities and opacities and address them.
There is a steady growth in research and demand for real quan- tum hardware in the Noisy Intermediate-Scale Quantum (NISQ) era of quantum computing. This prompts many third-party cloud providers to set up quantum hardware as a service that includes a wide range of qubit technologies and architectures to maximize performance at minimal cost. Quantum circuits submitted to these services are the fruits of the efforts invested by the designers. But these third-party cloud compilers (who offer more efficient alter- natives to established compilers) can make user circuits/programs vulnerable to various security breaches. Communication channels for transmitting quantum information also need to be developed such that there is end to end encryption. There is little to no visibil- ity on where the execution of the circuit is actually taking place. The success of the user program is highly reliant on the backend that was used for execution. Besides, the third-party provider and/or tools (e.g., hardware mapper and allocator) may be untrustworthy and execute the quantum circuits on less efficient and more error- prone hardware to conserve resources and maximize profit. These vulnerabilities in the quantum system could leak confidential data, cause loss of intellectual property rights of designers, cause loss of access control, corrupt user programs et cetera. Thus, it is imper- ative to identify these security vulnerabilities and create defense strategies to protect quantum programs, thus helping to maintain the integrity of quantum information across the software stack. My thesis aims to help address these vulnerabilities and opacities and address them.
Many third-party cloud providers set up quantum hardware as a service that includes a wide range of qubit technologies and architectures to maximize performance at minimal cost. However, there is little visibility to where the execution of the circuit is taking place. This situation is similar to the classical cloud. The difference in the quantum scenario is that the success of the user program is highly reliant on the backend used. Besides, the third-party provider may be untrustworthy and execute the quantum circuits on less efficient and more error-prone hardware to maximize profit. Thus, gaining visibility on the backend from various aspects will be valuable. Effective forensics can have many applications including establishing trust in quantum cloud services. We introduce the problem of forensics in the domain of quantum computing. We trace the coupling map of the hardware where the transpilation of the circuit took place from the transpiled program. We perform experiments on various coupling topologies (linear, T-shaped, H-shaped, and loop) on IBM backends. We can derive the coupling map from the transpiled circuits with complete accuracy for almost every transpiled circuit we considered. We could correctly trace 97.33% of the programs to the correct backend.
Third-party cloud providers offer quantum hardware as a service enabling flexibility to the customers to opt from varied quantum hardware, qubit technologies and topologies. However, the actual execution of the program on the desired target hardware remains opaque to the user. On one hand, the program performance, along with various other metadata such as cost, performance, & number of iterations to converge, is dependent on the quality of the backend chosen. on the other hand, the third-party provider and/or tools (e.g., hardware schedulers) may maximize profit by running the quantum circuits on poor quality backend while charging for the high quality backend. Existing approaches to mitigate this opaqueness rely on forensics of error rates and coupling topology from transpiled circuit. We note that program queue depth and execution time are well correlated with the backend and therefore, can reveal vital information about the hardware and aid in forensic analysis to address the opaqueness.
Quantum computing (QC) is an emerging paradigm with the potential to transform numerous application domains by addressing classically intractable problems. However, its growing presence in cyberspace has introduced new security and privacy challenges. Similar to classical computing systems, the QC stack including software and hardware relies extensively on third parties, many of which are emerging and trust-seeking or less-trusted. This stack often contains sensitive intellectual property (IP) that demands protection. Unique features of quantum systems can enable classical-style attacks: for instance, crosstalk in multitenant settings can facilitate fault-injection attacks, while malicious calibration services can misreport error rates or miscalibrate qubits to induce denial-of-service (DoS) conditions. Given the high cost and limited availability of likely trustworthy quantum hardware, users may be enticed to explore emerging and trust-seeking but cheaper and readily available quantum hardware, which can enable the stealth of IP and tampering of quantum programs and/or computation outcomes. Similarly, emerging compilation services may compromise circuit confidentiality or insert Trojans. Despite the strategic significance of QC and its potential to process sensitive information, its security and privacy concerns remain underexplored. This article presents a comprehensive overview of QC fundamentals, key vulnerabilities, recent attack vectors, and corresponding defenses, and concludes with directions for future research to strengthen the quantum security community.
Quantum computing leverages quantum mechanics to achieve computational advantages over classical hardware, but the use of third-party quantum compilers in the Noisy Intermediate-Scale Quantum (NISQ) era introduces risks of intellectual property (IP) exposure. We address this by proposing a novel obfuscation technique that protects proprietary quantum circuits by inserting additional quantum gates prior to compilation. These gates corrupt the measurement outcomes, which are later corrected through a lightweight classical post-processing step based on the inserted gate structure. Unlike prior methods that rely on complex quantum reversals, barriers, or physical-to-virtual qubit mapping, our approach achieves obfuscation using compiler-agnostic classical correction. We evaluate the technique across five benchmark quantum algorithms—Shor’s, QAOA, Bernstein-Vazirani, Grover’s, and HHL—using IBM’s Qiskit framework. The results demonstrate high Total Variation Distance (above 0.5) and consistently negative Degree of Functional Corruption (DFC), confirming both statistical and functional obfuscation. This shows that our method is a practical and effective solution for the security of quantum circuit designs in untrusted compilation flows.
The qubit technologies, basis gate set, noise behavior, speed and coupling architecture are among the various factors that vary among various backends. Although third-party cloud providers offering quantum hardware as a service offer lower cost and flexibility to the users to choose from several qubit technologies, quantum hardware, and coupling maps; the actual execution of the program is not clearly visible to the customer. The success of the user program, in addition to various other metadata such as cost, performance, & number of iterations to converge, depends on the error rate of the backend used. Moreover, the third-party provider and/or tools (e.g., hardware allocator and mapper) may hold insider/outsider adversarial agents to conserve resources and maximize profit by running the quantum circuits on error-prone hardware. Thus it is important to gain visibility of the backend from various perspectives of the computing process e.g., execution, transpilation and outcomes. In this paper, we estimate the error rate of the backend from the original and transpiled circuit. Although many quantum services providers publish the error rates of their backends, we assume that such information may not be accurate and/or correspond to the actual hardware allocated to the program. For the forensics we propose two complementary approaches. First, we exploit the fact that qubit mapping and routing steps of the transpilation process select qubits and qubit pairs with low gate errors to minimize overall error accumulation. We leverage this to rank qubit links into bins and compare with publicly available data we are able to assign a bin rank within a difference of 2 with respect to the actual bin for upto83.5%of the qubit links in IBM Sherbrooke and80%in IBM Brisbane, 127 qubit IBM backends. Second, we derive the error rates of the backends from a pool of programs by solving fidelity equations using numerical nonlinear optimizer. We achieve upto92.7%(97.3%)accuracy for single qubit (2 qubit) gate error rates.
Cloud-based quantum computingQuantum Computing (QC) introduces significant security and privacy risks to users’ intellectual property, including both program code and input data. In the absence of dedicated protections, quantum circuits submitted to remote services may be accessible to the cloud provider or compromised by malicious insiders. Furthermore, data embedded in these circuits remains susceptible to leakage during execution. This work proposes architectural and hardware enhancements for contemporary superconducting-qubit quantum computers to mitigate such threats. Drawing inspiration from classical Trusted Execution EnvironmentsTrusted Execution Environments (TEE) (TEEs), we define Quantum Trusted Execution EnvironmentsTrusted Execution Environments (TEE) (QTEEs): trusted hardware mechanisms designed to conceal or obfuscate quantum programs in cloud settings. We present two concrete instantiations, SoteriaQ and CASQUE, detailing their hardware support and required system software.