Secure dynamic multiparty quantum private comparison

AbstractWe propose a feasible and efficient dynamic multiparty quantum private comparison protocol that is fully secure against participant attacks. In the proposed scheme, two almost-dishonest third parties generate two random keys and send them to all participants. Every participant independently encrypts their private information with the encryption keys and sends it to the third parties. The third parties can analyze the equality of all or some participants’ secrets without gaining access to the secret information. New participants can dynamically join the protocol without the need for any additional conditions in the protocol. We provide detailed correctness and security analysis of the proposed protocol. Our security analysis of the proposed protocol against both inside and outside attacks proves that attackers cannot extract any secret information.

Download Full-text

Quantum Private Comparison of Arbitrary Single Qubit States Based on Swap Test

Chinese Physics B ◽

10.1088/1674-1056/ac4103 ◽

2021 ◽

Author(s):

Xi Huang ◽

Yan Chang ◽

Wen Cheng ◽

Min Hou ◽

Shi-Bin Zhang

Keyword(s):

Quantum State ◽

Private Information ◽

Security Analysis ◽

Entanglement Swapping ◽

Third Party ◽

Quantum Private Comparison ◽

Single Qubit ◽

Private Comparison ◽

Comparison Results ◽

Qubit States

Abstract In this paper, by using swap test, a quantum private comparison (QPC) protocol of arbitrary single qubit states with a semi-honest third party is proposed. The semi-honest third party (TP) is required to help two participants perform the comparison. She can record intermediate results and do some calculations in the whole process of the protocol execution, but she cannot conspire with any participants. In the process of comparison, TP cannot get two participants' private information except the comparison results. According to the security analysis, the proposed protocol can resist both outsider attacks and participant attacks. Compared with the existing QPC protocols, the proposed one does not require any entanglement swapping technology, and it can compare two participants' qubits by performing swap test, which is easier to implement with current technology. Meanwhile, the proposed protocol can compare secret integers. It encodes secret integers into the amplitude of quantum state rather than transfer them as binary representations, and the encoded quantum state is compared by performing swap test. Additionally, the proposed QPC protocol is extended to the QPC of arbitrary single qubit states by using multi-qubit swap test.

Download Full-text

CRYPTANALYSIS AND IMPROVEMENTS FOR THE QUANTUM PRIVATE COMPARISON PROTOCOL USING EPR PAIRS

International Journal of Quantum Information ◽

10.1142/s0219749913500391 ◽

2013 ◽

Vol 11 (04) ◽

pp. 1350039 ◽

Cited By ~ 21

Author(s):

CONG WANG ◽

GANG XU ◽

YI-XIAN YANG

Keyword(s):

Third Party ◽

Quantum Private Comparison ◽

Secret Information ◽

Epr Pairs ◽

Private Comparison ◽

Depth Analysis ◽

Feasible Solutions

In this paper, we carry out an in-depth analysis of the quantum private comparison (QPC) protocol with the semi-honest third party (TP). The security of QPC protocol using the EPR pairs is re-examined. Unfortunately, we find that TP can use the fake EPR pairs to steal all the secret information. Furthermore, we give two simple and feasible solutions to improve the original QPC protocol. It is shown that the improved protocol is secure, which can resist various kinds of attacks from both the outside eavesdroppers and the inside participants, even the semi-honest TP.

Download Full-text

Multiparty quantum private comparison with almost dishonest third parties for strangers

Quantum Information Processing ◽

10.1007/s11128-016-1498-2 ◽

2016 ◽

Vol 16 (2) ◽

Cited By ~ 16

Author(s):

Shih-Min Hung ◽

Sheng-Liang Hwang ◽

Tzonelih Hwang ◽

Shih-Hung Kao

Keyword(s):

Third Parties ◽

Quantum Private Comparison ◽

Private Comparison

Download Full-text

Security analysis of multi-party quantum private comparison protocol by model checking

Modern Physics Letters B ◽

10.1142/s021798491550089x ◽

2015 ◽

Vol 29 (18) ◽

pp. 1550089 ◽

Cited By ~ 3

Author(s):

Fan Yang ◽

Guowu Yang ◽

Yujie Hao ◽

Qingbin Luo ◽

Yuqi Wang

Keyword(s):

Model Checking ◽

Security Analysis ◽

Entangled States ◽

Probabilistic Model Checking ◽

Special Focus ◽

Quantum Private Comparison ◽

Analysis Method ◽

Private Comparison ◽

Security Properties ◽

Multi Body

This paper presents an analysis method for quantum information protocols based on model checking, with special focus on the quantum privacy comparison (QPC). The security properties of these protocols can be proved but in ways with much difficulty. Here we will discuss a probabilistic model checking tool — PRISM to verify specific properties of QPC protocol with multi-body and PRISM to verify specific properties of quantum private comparison (QPC) protocol with multi-party and d-dimensional entangled states.

Download Full-text

AN EFFICIENT PROTOCOL FOR THE QUANTUM PRIVATE COMPARISON OF EQUALITY WITH A FOUR-QUBIT CLUSTER STATE

International Journal of Quantum Information ◽

10.1142/s0219749912500451 ◽

2012 ◽

Vol 10 (04) ◽

pp. 1250045 ◽

Cited By ~ 25

Author(s):

GUO-AI XU ◽

XIU-BO CHEN ◽

ZHAN-HONG WEI ◽

MENG-JIAO LI ◽

YI-XIAN YANG

Keyword(s):

Private Information ◽

Cluster State ◽

Secure Communications ◽

Quantum Private Comparison ◽

Comparison Result ◽

Private Comparison

In this paper, we further research the quantum private comparison protocol with the semi-honest participant, in which two parties can test the equality of their information without revealing the content to anyone. Considering both the success of protocol and the security of information, we first give a reasonable and significant description about the semi-honest model in quantum secure communications. Moreover, based on the feature of four-qubit cluster state which has the great robust against decoherence, we propose a new protocol for the quantum private comparison. Our protocol ingeniously utilizes the special symmetry of the four-qubit cluster state to enhance the efficiency of comparison. This new protocol is secure. The participants only know the result of comparison; cannot know each other's private information. TP cannot learn anything about the private information, even about the comparison result and the length of secret inputs.

Download Full-text

Should Peacemakers Take Sides? Major Power Mediation, Coercion, and Bias

American Political Science Review ◽

10.1017/s0003055409090236 ◽

2009 ◽

Vol 103 (2) ◽

pp. 248-263 ◽

Cited By ~ 71

Author(s):

KATJA FAVRETTO

Keyword(s):

Private Information ◽

Third Parties ◽

Third Party ◽

Major Power ◽

The Balkans ◽

The Third ◽

Peaceful Settlement ◽

The Third Party

This paper focuses on powerful third parties whose interests in a conflict are closely aligned with a single disputant's interests. I show that such third-party bias reveals private information about an intervener's willingness to secure an agreement using force. When a highly biased power intervenes in a crisis, a peaceful settlement is likely because warring parties are certain the third party will enforce an agreement by military means. When an intervener shows less favoritism, negotiations tend to fail because the disputants doubt that it is committed to use force. Peace is again more likely when the third party is unbiased because such a party behaves as a mediator, seeking agreements both adversaries find acceptable. These findings, coupled with evidence from U.S. and British interventions in the Balkans, suggest a possible explanation for why major power intervention can bring about drastically different outcomes.

Download Full-text

Formation of Contract and Third Parties in Cambodia

10.1093/oso/9780198808114.003.0017 ◽

2018 ◽

Cited By ~ 2

Author(s):

Ly Tayseng

Keyword(s):

Academic Writing ◽

Case Law ◽

Civil Code ◽

Third Parties ◽

Third Party ◽

The Third ◽

Contract Formation ◽

The Law ◽

The Right ◽

Formal Requirements

This chapter gives an overview of the law on contract formation and third party beneficiaries in Cambodia. Much of the discussion is tentative since the new Cambodian Civil Code only entered into force from 21 December 2011 and there is little case law and academic writing fleshing out its provisions. The Code owes much to the Japanese Civil Code of 1898 and, like the latter, does not have a requirement of consideration and seldom imposes formal requirements but there are a few statutory exceptions from the principle of freedom from form. For a binding contract, the agreement of the parties is required and the offer must be made with the intention to create a legally binding obligation and becomes effective once it reaches the offeree. The new Code explicitly provides that the parties to the contract may agree to confer a right arising under the contract upon a third party. This right accrues directly from their agreement; it is not required that the third party declare its intention to accept the right.

Download Full-text

Contracts for the Benefit of Third Parties Under the Taiwan Civil Code

10.1093/oso/9780198808114.003.0016 ◽

2018 ◽

Author(s):

Sheng-Lin JAN

Keyword(s):

Civil Code ◽

Third Parties ◽

Third Party ◽

The Third ◽

Legal Relationship ◽

The Third Party ◽

Privity Of Contract

This chapter discusses the position of third party beneficiaries in Taiwan law where the principle of privity of contract is well established. Article 269 of the Taiwan Civil Code confers a right on the third party to sue for performance as long as the parties have at least impliedly agreed. This should be distinguished from a ‘spurious contract’ for the benefit of third parties where there is no agreement to permit the third party to claim. Both the aggrieved party and the third party beneficiary can sue on the contract, but only for its own loss. The debtor can only set off on a counterclaim arising from its legal relationship with the third party. Where the third party coerces the debtor into the contract, the contract can be avoided, but where the third party induces the debtor to contract with the creditor by misrepresentation, the debtor can only avoid the contract if the creditor knows or ought to have known of the misrepresentation.

Download Full-text