A Practical Semi-Quantum Signature Protocol with Improved Eavesdropping Detection

arxiv: 2604.15836 · v1 · submitted 2026-04-17 · 🪐 quant-ph

A Practical Semi-Quantum Signature Protocol with Improved Eavesdropping Detection

Zengyu Pang , Hua Xiang This is my paper

Pith reviewed 2026-05-10 08:28 UTC · model grok-4.3

classification 🪐 quant-ph

keywords semi-quantum signatureBell stateseavesdropping detectionquantum cryptographydigital signatureunforgeabilitytamperingpractical protocol

0 comments p. Extension

The pith

A semi-quantum signature protocol stays secure against tampering of already generated signatures.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper introduces a practical semi-quantum signature protocol based on Bell states. Only the signer needs full quantum capabilities while the other participants use classical operations. An improved eavesdropping-detection step, grounded in Bell-state correlations, is added to catch attempts to alter signatures after they have been produced. This fills a gap in prior schemes whose unforgeability proofs often omitted post-generation tampering. If the detection works, the protocol supports reliable quantum signatures in networks where not every device has quantum hardware.

Core claim

The protocol enables signature functionality in semi-quantum settings by letting the signer generate signatures with Bell states while other parties remain classical. It incorporates an enhanced eavesdropping check that explicitly guards against tampering of completed signatures, thereby preserving unforgeability under attacks that modify already-generated signatures.

What carries the argument

The improved eavesdropping-detection mechanism based on Bell-state correlations, which detects tampering of generated signatures without requiring full quantum capability from all participants.

If this is right

Only the signer requires quantum hardware, reducing the cost and complexity for other users.
Unforgeability holds even when adversaries target signatures after they have been created.
The protocol supports deployment in mixed quantum-classical networks without demanding full quantum power everywhere.
Security analysis covers a broader class of tampering attacks than many earlier semi-quantum schemes.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The same detection idea could be tested in other semi-quantum tasks such as key distribution.
Realistic noise models would need checking to confirm the detection rate remains high.
Integration with existing classical signature infrastructure could be examined for hybrid systems.

Load-bearing premise

The Bell-state correlations reliably flag any tampering of a completed signature without missing attacks or opening new vulnerabilities in the semi-quantum environment.

What would settle it

A concrete tampering attack that successfully alters a generated signature while evading the Bell-state-based detection checks.

Figures

Figures reproduced from arXiv: 2604.15836 by Hua Xiang, Zengyu Pang.

**Figure 1.** Figure 1: Signature process 3. Our SQS Protocol Our SQS protocol involves three parties: Alice, Bob, and a trusted third party, Trent. Alice is the signer and is responsible for signing messages, while Bob is the recipient who verifies the signature with the assistance of the trusted third party Trent. Only Alice is a quantum party with full quantum capabilities, Bob and Trent are classical parties. Let m denote the… view at source ↗

read the original abstract

Semi-quantum signature (SQS) schemes aim to enable quantum signature functionality in scenarios where only a subset of participants possess full quantum capabilities, thereby improving practical deployability while preserving quantum security advantages. Within this framework, we present a practical SQS protocol based on Bell states. The protocol is designed so that only the signer requires full quantum capability, significantly alleviating the quantum burden on the remaining participants. To strengthen security in semi-quantum environments, we incorporate an improved eavesdropping-detection mechanism that more effectively detects tampering. Compared with many existing schemes, which do not explicitly consider tampering of already generated signatures in their unforgeability analyses, the proposed protocol is designed to remain secure in the presence of such tampering.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The paper gives a signer-only quantum semi-quantum signature scheme with Bell states and explicit tampering checks, but the security argument is not yet shown to hold.

read the letter

The core contribution is a concrete SQS protocol that uses Bell states and limits full quantum operations to the signer alone. This does reduce the hardware load on verifiers and receivers compared with fully quantum schemes. The authors also try to handle tampering of already-signed messages in the unforgeability analysis, which the abstract notes is often left out of earlier work. That focus on post-generation tampering is the clearest practical angle they add. The improved eavesdropping check based on Bell correlations is presented as the mechanism that makes the scheme hold up under that threat. On the positive side, the construction is straightforward to describe and stays within the semi-quantum model without introducing extra participants or resources. The limitation is that the provided abstract contains no security proof, no attack model details, no parameter ranges, and no comparison tables. Without those derivations it is impossible to check whether the Bell-state detection actually catches the claimed tampering without opening new loopholes in the semi-quantum setting. The soundness therefore rests on an unverified assumption that the detection step works as intended. This paper is aimed at researchers already working on semi-quantum cryptography who want a new construction to test or extend. A reader looking for deployable ideas might extract the protocol steps, but anyone planning to cite or implement it would first need the full proofs and analysis. I would send it to peer review because the signer-only design and tampering angle are worth a referee's time to evaluate, even if the current version needs substantial strengthening on the security side.

Circularity Check

0 steps flagged

No circularity: new constructive protocol with independent security design

full rationale

The paper presents a new semi-quantum signature protocol based on Bell states in which only the signer requires full quantum capability. The improved eavesdropping-detection mechanism is introduced as an explicit design feature to handle tampering of already-generated signatures, a consideration the authors note is missing from many prior schemes. No equations or steps reduce by construction to fitted parameters, self-definitions, or load-bearing self-citations; the unforgeability claim rests on the protocol's structural choices rather than renaming or re-deriving prior results. The derivation is therefore self-contained as a constructive proposal.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The protocol rests on standard quantum assumptions such as the properties of Bell states and the no-cloning theorem; no free parameters, new entities, or ad-hoc axioms are mentioned in the abstract.

axioms (2)

standard math Bell states exhibit the expected quantum correlations under local measurements
Invoked implicitly as the basis for both signature generation and eavesdropping detection.
domain assumption Semi-quantum participants can reliably perform classical operations and communicate without introducing quantum errors
Required for the reduced quantum burden on non-signers.

pith-pipeline@v0.9.0 · 5407 in / 1236 out tokens · 23985 ms · 2026-05-10T08:28:22.823490+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

43 extracted references · 1 canonical work pages

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L. Ding, X. Xin, Q. Yang, Y. Sang, Security analysis and improvements of xor arbitrated quantum signature-based ghz state, Modern Physics Letters A 37 (02) (2022) 2250008

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T.Zheng, Y.Chang, L.Yan, S.-B.Zhang, Semi-quantumproxysignatureschemewithquantum walk-based teleportation, International Journal of Theoretical Physics 59 (10) (2020) 3145– 3155

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L.-Y. Chen, Q. Liao, R.-C. Tan, L.-H. Gong, H.-Y. Chen, Offline arbitrated semi-quantum signature scheme with four-particle cluster state, International Journal of Theoretical Physics 59 (12) (2020) 3685–3695

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C. Xia, H. Li, J. Hu, Semi-quantum digital signature protocol based on einstein–podolsky– rosen steering, Journal of Physics A: Mathematical and Theoretical 55 (32) (2022) 325302

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X. Zhao, T. Chen, A novel semi-quantum co-signature scheme based on ghz states and four- particle cluster states, International Journal of Theoretical Physics 62 (4) (2023) 78

2023
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2025
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2022
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C.-W. Yang, J. Lin, C.-W. Tsai, C.-L. Cheng, Cryptanalysis of a semi-quantum bi-signature scheme based on w states, Entropy 24 (10) (2022) 1408

2022
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He, Z.-Z

R.-Z. He, Z.-Z. Li, Q.-H. Wang, Y.-J. Li, Z.-C. Li, Semi-quantum ring signature protocol based on multi-particle ghz state: Rz. he et al., Quantum Information Processing 22 (9) (2023) 337

2023
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Zhang, J.-H

L. Zhang, J.-H. Zhang, X.-J. Xin, M. Huang, C.-Y. Li, Semi-quantum designated verifier signature scheme, International Journal of Theoretical Physics 62 (12) (2023) 254. 15

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Zhang, X

T. Zhang, X. Xin, B. Jiang, C. Li, F. Li, Bell state-based semi-quantum signature scheme with arbitrator, Optical and Quantum Electronics 56 (1) (2024) 131

2024
[33]

Shang, Y

Z. Shang, Y. Han, X. Xin, C. Li, L. Gong, F. Li, Semi-quantum multi-signature protocol based on permutation, Quantum Information Processing 25 (3) (2026) 77

2026
[34]

Y. Tian, J. Li, X.-B. Chen, C.-Q. Ye, H.-J. Li, An efficient semi-quantum secret sharing protocol of specific bits, Quantum Information Processing 20 (6) (2021) 217

2021
[35]

F. He, X. Xin, C. Li, F. Li, Security analysis of the semi-quantum secret-sharing protocol of specific bits and its improvement, Quantum Information Processing 23 (2) (2024) 51

2024
[36]

X.Wen, X.Niu, L.Ji, Y.Tian, Aweakblindsignatureschemebasedonquantumcryptography, Optics Communications 282 (4) (2009) 666–669

2009
[37]

C. E. Shannon, Communication theory of secrecy systems, The Bell system technical journal 28 (4) (1949) 656–715

1949
[38]

S. M. Bellovin, Frank miller: Inventor of the one-time pad, Cryptologia 35 (3) (2011) 203–222

2011
[39]

L. Yang, B. Yang, J. Pan, Quantum public-key encryption protocols with information-theoretic security, in: Quantum Optics II, Vol. 8440, SPIE, 2012, pp. 71–77

2012
[40]

Y. Li, X. Chong, L. Bao, Quantum probabilistic encryption scheme based on conjugate coding, China Communications 10 (2) (2013) 19–26

2013
[41]

A. J. Menezes, P. C. Van Oorschot, S. A. Vanstone, Handbook of applied cryptography, CRC press, 2018

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[42]

Cabello, Quantum key distribution in the holevo limit, Physical Review Letters 85 (26) (2000) 5635

A. Cabello, Quantum key distribution in the holevo limit, Physical Review Letters 85 (26) (2000) 5635

2000
[43]

H. Liu, X. Xin, Y. Han, L. Gong, C. Li, Quantum signature with formal security proof, Quantum Information Processing 24 (11) (2025) 353. 16

2025

[1] [1]

P. W. Shor, Polynomial-time algorithms for prime factorization and discrete logarithms on a quantum computer, SIAM review 41 (2) (1999) 303–332

1999

[2] [2]

Gennaro, T

R. Gennaro, T. Rabin, H. Krawczyk, Rsa-based undeniable signatures, Journal of cryptology 13 (2000) 397–416

2000

[3] [3]

Johnson, A

D. Johnson, A. Menezes, S. Vanstone, The elliptic curve digital signature algorithm (ecdsa), International journal of information security 1 (2001) 36–63

2001

[4] [4]

Huang, Z

Y. Huang, Z. Su, F. Zhang, Y. Ding, R. Cheng, Quantum algorithm for solving hyperelliptic curve discrete logarithm problem, Quantum Information Processing 19 (2) (2020) 62

2020

[5] [5]

L. K. Grover, Quantum mechanics helps in searching for a needle in a haystack, Physical review letters 79 (2) (1997) 325

1997

[6] [6]

C. H. Bennett, G. Brassard, Quantum cryptography: Public key distribution and coin tossing, Theoretical computer science 560 (2014) 7–11

2014

[7] [7]

C. H. Bennett, G. Brassard, An update on quantum cryptography, in: Workshop on the theory and application of cryptographic techniques, Springer, 1984, pp. 475–480

1984

[8] [8]

C. H. Bennett, Quantum cryptography using any two nonorthogonal states, Physical review letters 68 (21) (1992) 3121

1992

[9] [9]

Quantum Digital Signatures

D. Gottesman, I. Chuang, Quantum digital signatures, arXiv preprint quant-ph/0105032 (2001)

work page Pith review arXiv 2001

[10] [10]

G. Zeng, C. H. Keitel, Arbitrated quantum-signature scheme, Physical review A 65 (4) (2002) 042312

2002

[11] [11]

Y.-G.Yang, Z.Zhou, Y.-W.Teng, Q.-Y.Wen, Arbitratedquantumsignaturewithanuntrusted arbitrator, The European Physical Journal D 61 (2011) 773–778

2011

[12] [12]

Luo, X.-B

M.-X. Luo, X.-B. Chen, D. Yun, Y.-X. Yang, Quantum signature scheme with weak arbitrator, International Journal of Theoretical Physics 51 (2012) 2135–2142

2012

[13] [13]

X. Zou, D. Qiu, P.Mateus, Security analyses and improvement ofarbitrated quantum signature with an untrusted arbitrator, International Journal of Theoretical Physics 52 (2013) 3295–3305

2013

[14] [14]

Su, W.-M

Q. Su, W.-M. Li, Improved quantum signature scheme with weak arbitrator, International Journal of Theoretical Physics 52 (2013) 3343–3352

2013

[15] [15]

X. Xin, Q. He, Z. Wang, Q. Yang, F. Li, Efficient arbitrated quantum signature scheme without entangled states, Modern Physics Letters A 34 (21) (2019) 1950166. 14

2019

[16] [16]

X. Xin, Q. He, Z. Wang, Q. Yang, F. Li, Security analysis and improvement of an arbitrated quantum signature scheme, Optik 189 (2019) 23–31

2019

[17] [17]

Zheng, C

X.-Y. Zheng, C. Kuang, Arbitration quantum signature protocol based on xor encryption, International Journal of Quantum Information 18 (05) (2020) 2050025

2020

[18] [18]

L. Ding, X. Xin, Q. Yang, Y. Sang, Security analysis and improvements of xor arbitrated quantum signature-based ghz state, Modern Physics Letters A 37 (02) (2022) 2250008

2022

[19] [19]

Boyer, D

M. Boyer, D. Kenigsberg, T. Mor, Quantum key distribution with classical bob, in: 2007 First International Conference on Quantum, Nano, and Micro Technologies (ICQNM’07), IEEE, 2007, pp. 10–10

2007

[20] [20]

Boyer, M

M. Boyer, M. Katz, R. Liss, T. Mor, Experimentally feasible protocol for semiquantum key distribution, Physical Review A 96 (6) (2017) 062335

2017

[21] [21]

X.Zou, D.Qiu, L.Li, L.Wu, L.Li, Semiquantum-keydistributionusinglessthanfourquantum states, Physical Review A—Atomic, Molecular, and Optical Physics 79 (5) (2009) 052312

2009

[22] [22]

Zhao, H.-Y

X.-Q. Zhao, H.-Y. Chen, Y.-Q. Wang, N.-R. Zhou, Semi-quantum bi-signature scheme based on w states, International Journal of Theoretical Physics 58 (10) (2019) 3239–3251

2019

[23] [23]

T.Zheng, Y.Chang, L.Yan, S.-B.Zhang, Semi-quantumproxysignatureschemewithquantum walk-based teleportation, International Journal of Theoretical Physics 59 (10) (2020) 3145– 3155

2020

[24] [24]

L.-Y. Chen, Q. Liao, R.-C. Tan, L.-H. Gong, H.-Y. Chen, Offline arbitrated semi-quantum signature scheme with four-particle cluster state, International Journal of Theoretical Physics 59 (12) (2020) 3685–3695

2020

[25] [25]

C. Xia, H. Li, J. Hu, Semi-quantum digital signature protocol based on einstein–podolsky– rosen steering, Journal of Physics A: Mathematical and Theoretical 55 (32) (2022) 325302

2022

[26] [26]

X. Zhao, T. Chen, A novel semi-quantum co-signature scheme based on ghz states and four- particle cluster states, International Journal of Theoretical Physics 62 (4) (2023) 78

2023

[27] [27]

Yang, Semi-quantum signature protocol using epr steering and single photons, Annalen der Physik 537 (2) (2025) 2400260

C.-W. Yang, Semi-quantum signature protocol using epr steering and single photons, Annalen der Physik 537 (2) (2025) 2400260

2025

[28] [28]

Yang, C.-L

C.-W. Yang, C.-L. Cheng, Semi-quantum bi-signature scheme based on bell states, Modern Physics Letters A 37 (39n40) (2022) 2250254

2022

[29] [29]

C.-W. Yang, J. Lin, C.-W. Tsai, C.-L. Cheng, Cryptanalysis of a semi-quantum bi-signature scheme based on w states, Entropy 24 (10) (2022) 1408

2022

[30] [30]

He, Z.-Z

R.-Z. He, Z.-Z. Li, Q.-H. Wang, Y.-J. Li, Z.-C. Li, Semi-quantum ring signature protocol based on multi-particle ghz state: Rz. he et al., Quantum Information Processing 22 (9) (2023) 337

2023

[31] [31]

Zhang, J.-H

L. Zhang, J.-H. Zhang, X.-J. Xin, M. Huang, C.-Y. Li, Semi-quantum designated verifier signature scheme, International Journal of Theoretical Physics 62 (12) (2023) 254. 15

2023

[32] [32]

Zhang, X

T. Zhang, X. Xin, B. Jiang, C. Li, F. Li, Bell state-based semi-quantum signature scheme with arbitrator, Optical and Quantum Electronics 56 (1) (2024) 131

2024

[33] [33]

Shang, Y

Z. Shang, Y. Han, X. Xin, C. Li, L. Gong, F. Li, Semi-quantum multi-signature protocol based on permutation, Quantum Information Processing 25 (3) (2026) 77

2026

[34] [34]

Y. Tian, J. Li, X.-B. Chen, C.-Q. Ye, H.-J. Li, An efficient semi-quantum secret sharing protocol of specific bits, Quantum Information Processing 20 (6) (2021) 217

2021

[35] [35]

F. He, X. Xin, C. Li, F. Li, Security analysis of the semi-quantum secret-sharing protocol of specific bits and its improvement, Quantum Information Processing 23 (2) (2024) 51

2024

[36] [36]

X.Wen, X.Niu, L.Ji, Y.Tian, Aweakblindsignatureschemebasedonquantumcryptography, Optics Communications 282 (4) (2009) 666–669

2009

[37] [37]

C. E. Shannon, Communication theory of secrecy systems, The Bell system technical journal 28 (4) (1949) 656–715

1949

[38] [38]

S. M. Bellovin, Frank miller: Inventor of the one-time pad, Cryptologia 35 (3) (2011) 203–222

2011

[39] [39]

L. Yang, B. Yang, J. Pan, Quantum public-key encryption protocols with information-theoretic security, in: Quantum Optics II, Vol. 8440, SPIE, 2012, pp. 71–77

2012

[40] [40]

Y. Li, X. Chong, L. Bao, Quantum probabilistic encryption scheme based on conjugate coding, China Communications 10 (2) (2013) 19–26

2013

[41] [41]

A. J. Menezes, P. C. Van Oorschot, S. A. Vanstone, Handbook of applied cryptography, CRC press, 2018

2018

[42] [42]

Cabello, Quantum key distribution in the holevo limit, Physical Review Letters 85 (26) (2000) 5635

A. Cabello, Quantum key distribution in the holevo limit, Physical Review Letters 85 (26) (2000) 5635

2000

[43] [43]

H. Liu, X. Xin, Y. Han, L. Gong, C. Li, Quantum signature with formal security proof, Quantum Information Processing 24 (11) (2025) 353. 16

2025