Security Analysis of Ekert-type QKD Protocol Coming Under Cloning Attacks

Abstract

We analyze the security of an Ekert type bipartite key distribution protocol coming under cloning attacks by an untrusted observer. Precisely, an eavesdropper is assumed to intercept and apply an asymmetric, phase-variant cloner on one or both qubits which are transmitted over public channel from an authenticated source to the trusted parties. We partially characterize two-qubit states from the perspective of designing a QKD protocol that can generate a distillable secret key among the trusted users even under such cloning attacks. We rely upon Devetak Winter framework for computing key rate so as to identify states, which when used in the protocol, secret-key can be distilled. Utility of an entangled state, for designing a successful QKD protocol, changes from single-qubit to double-qubits cloning attacks. Interestingly, we can distinguish some useful families of two-qubit entangled states when only one of the transmitted qubits is cloned by a malicious third party.

Where Quantum Fourier Sampling Stops Short: A Three-Gate Audit Protocol for Delay-PUF Security Models
Owen Friedewald, Ali Shiri Sichani, Chi-Ren Shyu
arXiv2 Oct 2026PreprintCC BY 4.0Full textQuantum physics & quantum informationarXiv
Constraints for Physical Gauge Groups Coming from the Causal Action Principle
Felix Finster, Niels Gresnigt
arXiv21 Sep 2026PreprintarXiv licenceFull textMathematical physics High-energy & particle physicsarXiv
Acoustic cloning
Johan O.A. Robertsson, Dirk-Jan van Manen, Jonas Müller +4
Physical Review Applied9 Oct 2026Peer-reviewedLicence not statedFull text4 citedGeneral physicsHAL
Encrypted cloning of qubits is able to serve as a quantum primitive, already on non-error-corrected quantum hardware
Koji Yamaguchi, Leon Rullkötter, Ibrahim Shehzad +3
Physical Review Research27 Oct 2026Peer-reviewedPublisher termsAtomic, molecular & optical physicsCrossref
Nonergodicity from Hilbert-Subspace Cloning
Yuuya Chiba, Ryusuke Hamazaki
arXiv16 Oct 2026PreprintarXiv licenceFull textQuantum physics & quantum information Statistical & nonlinear physicsarXiv

Cite

BibTeX RIS

BibTeX

@misc{mukherjee2026security,
  title = {{Security Analysis of Ekert-type QKD Protocol Coming Under Cloning Attacks}},
  author = {Kaushiki Mukherjee and Sumana Karmakar},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.37337},
  eprint = {2610.37337},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.37337},
  note = {CC BY 4.0},
}

RIS

TY  - UNPB
TI  - Security Analysis of Ekert-type QKD Protocol Coming Under Cloning Attacks
AU  - Kaushiki Mukherjee
AU  - Sumana Karmakar
PY  - 2026
DA  - 2026/10/27
PB  - arXiv
DO  - 10.48550/arxiv.2610.37337
UR  - https://arxiv.org/abs/2610.37337
AB  - We analyze the security of an Ekert type bipartite key distribution protocol coming under cloning attacks by an untrusted observer. Precisely, an eavesdropper is assumed to intercept and apply an asymmetric, phase-variant cloner on one or both qubits which are transmitted over public channel from an authenticated source to the trusted parties. We partially characterize two-qubit states from the perspective of designing a QKD protocol that can generate a distillable secret key among the trusted users even under such cloning attacks. We rely upon Devetak Winter framework for computing key rate so as to identify states, which when used in the protocol, secret-key can be distilled. Utility of an entangled state, for designing a successful QKD protocol, changes from single-qubit to double-qubits cloning attacks. Interestingly, we can distinguish some useful families of two-qubit entangled states when only one of the transmitted qubits is cloned by a malicious third party.
ER  -

Abstract

Related

Cite