Are Quantum Computers Really Running Your Quantum Circuits?

Running a quantum algorithm on today's quantum hardware requires several transformations of the original circuit, often involving optimization and adaptation steps. These transformations, however, can introduce discrepancies between the intended and the executed circuit. Such mismatches create a subtle but critical attack surface, where private data may leak or computation results may be altered. This poster presents concrete examples of these threats on IBM quantum devices and proposes a lightweight detection and mitigation strategy to protect the integrity of quantum computations.