Verification of Quantum Computations Without Trusted Preparations or Measurements
Elham Kashefi, Dominik Leichtle, Luka Music, Harold Ollivier · Advanced Quantum Technologies · 2026
ABSTRACT With the advent of delegated quantum computing as a service, verifying the integrity of quantum computations is becoming a question of great importance. Existing information‐theoretically Secure Delegated Quantum Computing (SDQC) protocols require the client to possess the ability to perform either trusted state preparations or measurements. Whether it is possible to verify universal quantum computations with information‐theoretic security without trusted preparations or measurements was an open question so far. In this paper, we settle this question in the affirmative by presenting a modular, composable, and efficient way to turn known verification schemes into protocols that rely only on trusted gates. Our first contribution is an extremely lightweight reduction of the problem of quantum verification for to the trusted application of single‐qubit rotations around the axis and bit flips. The second construction presented in this work shows that it is possible to information‐theoretically verify arbitrary quantum computations without trusted preparations or measurements if the verifier can perform two‐qubit gates on a register whose size is logarithmic in the security parameter. Our third contribution extends these two results to the multi‐party setting in which multiple mutually distrustful clients delegate a joint computation to a potentially malicious server.