Confidential Integrity Verification via quantum teleportation

Abstract Standard post-quantum cryptography signatures can verify authenticity but inevitably compromise confidentiality by exposing message digests to the public channel—a critical vulnerability for low-entropy or high-security messages. To overcome this, we propose a Confidential Integrity Verification framework that functionally operates as a secure two-party equality test (Quantum Private Comparison). This framework verifies the integrity of shared messages without revealing their digests. Unlike classical and quantum authenticated encryption schemes, our protocol requires no pre-shared symmetric keys; it leverages post-quantum cryptography solely for authenticating the initial entanglement purification. The message equality comparison itself achieves information-theoretic confidentiality via quantum state teleportation. We demonstrate that even under realistic noisy channels, the authentication error probability can be suppressed below 10^-9 with only 194 entangled pairs. This resource efficiency, combined with intrinsic immunity to “harvest now, decrypt later” attacks on the digest, provides an end-to-end, quantum-resistant solution ideal for verifying privacy-sensitive information in quantum networks, such as data post-processing in quantum key distribution.