Quantum Image Encryption with Reduced Gate Complexity for Gate-Efficient Encryption Pipelines in IoT Networks

In IoT networks and systems, the security of digital image data is a critical concern, which becomes even more critical in the post-quantum era where traditional encryption schemes will be vulnerable and can be easily compromised. This paper introduces a gate-efficient Quantum Image Encryption scheme that comprises pre-encryption quantum compression and chaos-based qubit encryption. By simplifying the quantum circuits that encode classical images into their quantum representations, the proposed scheme reduces the total number of quantum gates required before the actual encryption begins. This results in a more gate-efficient encryption pipeline for resource-constrained IoT systems. The encryption scheme comprises a quantum compression stage—by employing Boolean expression minimization— to simplify the quantum circuits in image preparation phase, followed by a two-stage encryption mechanism that employs quantum cellular automata and chaos-based qubit transformations. Extensive evaluation against key security parameters demonstrates close-to-ideal results for information entropy, and correlation analysis. The scheme also exhibits strong resilience against differential attacks, proving its effectiveness in securing image data for IoT devices in post-quantum environments.