Existential Unforgeability in Quantum Authentication From Quantum Physical Unclonable Functions Based on Random von Neumann Measurement

Physical Unclonable Functions (PUFs) leverage inherent, non-clonable physical randomness to generate unique input-output pairs, serving as secure fingerprints for cryptographic protocols like authentication.Quantum PUFs (QPUFs) extend this concept by using quantum states as inputoutput pairs, offering advantages over classical PUFs, such as challenge reusability via public channels and eliminating the need for trusted parties due to the no-cloning theorem.Recent literature introduced a generalized mathematical framework for QPUFs, demonstrating that no random unitary QPUF can achieve existential unforgeability against Quantum Polynomial Time (QPT) adversaries.Additionally, we introduce a second model where the QPUF functions as a nonunitary quantum channel, which also guarantees existential unforgeability.These are the first models in the literature to demonstrate such a high level of provable security.Finally, we show that the Quantum Phase Estimation (QPE) protocol, applied to a Haar random unitary, serves as an approximate implementation of the second type of QPUF by approximating a von Neumann measurement on the unitary's eigenbasis.