arXiv subjects

Tzonelih Hwang

Publications and source records attributed to Tzonelih Hwang.

31 records · Page 2Linked to original sources

arXiv2016

Multiparty Quantum Private Comparsion with Individually Dishonest Third Parties for Strangers

This study explores a new security problem existing in various state-of-the-art quantum private comparison (QPC) protocols, where a malicious third-party (TP) announces fake comparison (or intermediate) results. In this case, the participants could eventually be led to a wrong direction and the QPC will become fraudulent. In order to resolve this problem, a new level of trustworthiness for TP is defined and a new QPC protocol is proposed, where a second TP is introduced to monitor the first one. Once a TP announces a fake comparison (or intermediate) result, participants can detect the fraud immediately. Besides, due to the introduction of the second TP, the proposed protocol allows strangers to compare their secrets privately, whereas the state-of-the-art QPCs require the involved clients to know each other before running the protocol.

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arXiv2015

Comment on "An arbitrated quantum signature protocol based on the chained CNOT operations encryption"

In 2015, Li et al. (Quantum Inf Process (2015) 14:2171-2181) proposed an arbitrated quantum signature (AQS) scheme based on the chained controlled-NOT operations encryption. However, this paper points out that in their scheme an attacker can forge a signature without being detected. Therefore, Li et al.'s AQS scheme cannot satisfy the unforgeability and non-repudiation property.

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arXiv2015

Comment on "An arbitrated quantum signature scheme with fast signing and verifying"

Recently, Liu et al. (Quantum Inf Process (2014) 13:491-502) proposed an arbitrated quantum signature (AQS) scheme, where a signature receiver (Bob) can verify the signer's signature through the help of a trusted arbitrator. However, this paper shows that a malicious Bob can perform the existential forgery of the signature under the chosen message attack without being detected.

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arXiv2015

Quantum Entanglement Establishment between two Strangers

This paper presents the first quantum entanglement establishment scheme for strangers who neither pre-share any secret nor have any authenticated classical channel between them. The proposed protocol requires only the help of two almost dishonest third parties (TPs) to achieve the goal. The security analyses show that the proposed protocol is secure against not only an external eavesdropper's attack, but also the TP's attack.

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arXiv2015

Comment on 'Improving the security of protocols of quantum key agreement solely using Bell states and Bell measurement'

Designing a quantum key agreement (QKA) protocol is always a challenging task, because both the security and the fairness properties have to be considered simultaneously. Recently, Zhu et al. (Quantum Inf Process 14(11): 4245-4254) pointed out that Shukla et al.'s QKA protocol (Quantum Inf Process 13(11): 2391-2405) has some security flaws (which lead to the Participant Attack). Moreover, they proposed an improvement to avoid these weaknesses. However this study points out that the improved protocol also suffers from a colluding attack, i.e., two dishonest participants in the protocol can collaborate to manipulate the final secret key without being detected.

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arXiv2015

Blind Quantum Computation without Trusted Center

Blind quantum computation (BQC) protocol allows a client having partially quantum ability to del- egate his quantum computation to a remote quantum server without leaking any information about the input, the output and the intended computation. Recently, many BQC protocols have been proposed with the intention to make the ability of client more classical. In this paper, we propose two BQC protocols, in which the client does not have to generate photons, but only has to perform either rotation or reorder on the received photons.

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arXiv2015

On the Security of Two Blind Quantum Computations

Blind quantum computation (BQC) protocol allows a client having partial quantum ability to delegate his quantum computation to a remote quantum server without leaking any information about the input, the output and the intended computation to the server. Several BQC protocols have been proposed, e.g., Li et al. in [1] proposed a triple-server BQC protocol and Xu et al. in [2] proposed a single-server BQC protocol. Though both papers claimed that their protocols can satisfy the requirement of privacy, this paper points out a security loophole in their protocols. With that the server can reveal the private information of the client.

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arXiv2015

Authenticated Semi-quantum Direct Communication Protocols using Bell States

This study presents the first two authenticated semi-quantum direct communication (ASQDC) protocols without using any classical channel. By pre-sharing the master secret key between two communicants, a sender with advanced quantum devices can transmit a secret message to a receiver who can only perform classical operations without any information leakage. The receiver is then capable of verifying the message up to the single qubit level, i.e., a one-qubit modification of the transmitted quantum sequence can be detected with a probability close to 1. Moreover, the proposed protocols are resistant to several well-known attacks.

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arXiv2013

Multiparty Quantum Remote Control

This paper proposes a multiparty quantum remote control (MQRC) protocol, which allows several controllers to perform remote operations independently on a target state based on a shared entanglement of Greenberger-Home-Zeilinger (GHZ) state.

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arXiv2012

Comment on "Security analysis and improvements of arbitrated quantum signature schemes"

Recently, Zou et al. [Phys. Rev. A 82, 042325 (2010)] demonstrated that two arbitrated quantum signature (AQS) schemes are not secure, because an arbitrator cannot arbitrate the dispute between two users when a receiver repudiates the integrity of a signature. By using a public board, Zou et al. proposed two AQS schemes to solve the problem. This work shows that the same security problem may exist in Zou et al.'s schemes. Moreover, a malicious verifier, Bob, can actively negate a signed order if he wants to. This attack, a special case of denial-of-service (DoS) attack mentioned in [Phys. Rev. Lett. 91, 109801 (2003)], is important in quantum cryptography. Bob may get some benefits with this DoS attack, since he can actively deny Alice's signed order without being detected. This work also shows that a malicious signer can reveal the verifier's secret key without being detected by using Trojan-horse attacks.

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arXiv2011

Comment on "Semiquantum secret sharing using entangled states"

Recently, Li et al. [Phys. Rev. A, 82(2), 022303] presented two semi-quantum secret sharing (SQSS) protocols using GHZ-like states. The proposed schemes are rather practical because only the secret dealer requires to equip with advanced quantum devices such as quantum memory, whereas the other agents can merely perform classical operations to complete the secret sharing. However, this study points out that a security pitfall exists in the eavesdropping check phase of both schemes that could mount to an Intercept-resend attack and a Trojan horse attack on the two schemes, respectively, to disclose the other agent's shadow, and further to reveal the master key of the SQSS, which contradicts to the security requirement of a QSS. Fortunately, two possible solutions are proposed to avoid this security pitfall.

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arXiv2011

Quantum Secret Authentication Code

This study proposes a quantum secret authentication code for protecting the integrity of secret quantum states. Since BB84[1] was first proposed, the eavesdropper detection strategy in almost all quantum cryptographic protocols is based on the random sample discussion, in which the probability of eavesdropper detection is depending on the number of check qubits eavesdropped by the eavesdropper. Hence, if the eavesdropper interferes only a few qubits of the transmitted quantum sequence, then the detection probability will be very low. This study attempts to propose a quantum secret authentication code to solve this problem. With the use of quantum secret authentication code, not only is the probability of eavesdropper detection guaranteed to be evenly distributed no matter how many qubits had been eavesdropped, but also can the quantum transmission efficiency be highly enhanced.

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arXiv2011

On the "Security analysis and improvements of arbitrated quantum signature schemes"

Recently, Zou et al. [Phys. Rev. A 82, 042325 (2010)] pointed out that two arbitrated quantum signature (AQS) schemes are not secure, because an arbitrator cannot arbitrate the dispute between two users when a receiver repudiates the integrity of a signature. By using a public board, they try to propose two AQS schemes to solve the problem. This work shows that the same security problem may exist in their schemes and also a malicious party can reveal the other party's secret key without being detected by using the Trojan-horse attacks. Accordingly, two basic properties of a quantum signature, i.e. unforgeability and undeniability, may not be satisfied in their scheme.

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