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Ternary Quantum Eraser Cryptography

Quantum Physics 2026-04-24 v2

Abstract

Quantum key distribution protocols based on the quantum eraser phenomenon offer an operational advantage: automatic identification of matching and mismatching encoding choices through interference, eliminating basis reconciliation. However, binary quantum eraser implementations permit an eavesdropper to recover Alice's encoded bit with 85%85\% probability. To overcome this constraint, we introduce a ternary quantum eraser protocol employing three polarization states with 120120^\circ angular separation, transmitted in three-photon groups with randomized temporal ordering. This extension achieves enhanced security through two complementary mechanisms. First, the reduced distinguishability of symmetrically-arranged quantum states limits single-photon discrimination. Second, the combinatorial complexity of unknown photon ordering constrains multi-photon eavesdropping strategies. Security analysis against individual eavesdropping attacks within the four-dimensional path-polarization Hilbert space establishes that an eavesdropper's maximum success probability is bounded at 54%54\%, substantially below the binary discrimination bound. The protocol maintains a binary-equivalent efficiency of 0.30 bits per photon, comparable to established binary QKD protocols at the sifted-rate level, while preserving the operational simplicity inherent to quantum eraser cryptography.

Keywords

Cite

@article{arxiv.2604.12577,
  title  = {Ternary Quantum Eraser Cryptography},
  author = {Ahmed Halawani and Yahya Meshalwi Khabrani and Abdulaziz Al-Mogheeth and Zheng-Hong Li and M. Al-Amri},
  journal= {arXiv preprint arXiv:2604.12577},
  year   = {2026}
}
R2 v1 2026-07-01T12:08:32.634Z