To detect frauds by a dealer or some participants, researchers have proposed verifiable threshold quantum state sharing (VTQSTS) schemes. However, the existing VTQSTS schemes either have lowcomputation efficiency or weak security. In this paper, a verifiable (t, n) threshold quantum state sharing against denial attack (VTQSTS-ADA) scheme is proposed to overcome the above limitations, in which the dealer Alice encodes the quantum secret sequence into two quantum message sequences and a quantum signature sequence. First, for each participant in the authorization subset, the received quantum signature sequence is validated by a quantum verification algorithm, and then a unitary transformation with a rotation key is performed on the received quantum message sequence; next, a new quantum signature sequence is generated by a quantum signature algorithm with the signature key. Each participant sends the new message sequences and signature sequence to the next participant. The original quantum secret sequence can be reconstructed when t(t ≤ n) participants collaborate. The security analysis shows that the proposed VTQSTS-ADA scheme can detect the fraud instances raised by the dealer and participants and provide stronger security such as resisting denial attacks and man-in-middle attacks compared with the existing schemes. The performance analysis shows that the proposed VTQSTS-ADA scheme outperforms the earlier VTQSTS scheme and is comparable to the recent scheme.
A Verifiable (t,n) Threshold Quantum State Sharing Against Denial Attack
To detect frauds by a dealer or some participants, researchers have proposed verifiable threshold quantum state sharing (VTQSTS) schemes. However, the existing VTQSTS schemes either have lowcomputation efficiency or weak security. In this paper, a verifiable (t, n) threshold quantum state sharing against denial attack (VTQSTS-ADA) scheme is proposed to overcome the above limitations, in which the dealer Alice encodes the quantum secret sequence into two quantum message sequences and a quantum signature sequence. First, for each participant in the authorization subset, the received quantum signature sequence is validated by a quantum verification algorithm, and then a unitary transformation with a rotation key is performed on the received quantum message sequence; next, a new quantum signature sequence is generated by a quantum signature algorithm with the signature key. Each participant sends the new message sequences and signature sequence to the next participant. The original quantum secret sequence can be reconstructed when t(t ≤ n) participants collaborate. The security analysis shows that the proposed VTQSTS-ADA scheme can detect the fraud instances raised by the dealer and participants and provide stronger security such as resisting denial attacks and man-in-middle attacks compared with the existing schemes. The performance analysis shows that the proposed VTQSTS-ADA scheme outperforms the earlier VTQSTS scheme and is comparable to the recent scheme.
A verifiable (t, n) threshold quantum secret sharing scheme with sequential communication was proposed recently. In this work, we analyze its security and then give two new participant attacks. Using the first participant attack, the first participant can obtain the dealer's secrets by himself with nonzero probability without being detected. Using the second participant attack, a dishonest participant can gain access to the dealer's secrets by himself in the secret reconstruction phase while he can make the other participants recover false secrets instead of the real ones without being detected. Furthermore, we present an effective way to prevent these attacks.
Quantum state sharing (QSTS) is a hot topic in quantum cryptography. However, majority of the current structures cannot resist the participant's fraud well during the initial state reconstruction phase. Especially, verifiable QSTS scheme which can be used to share unknown quantum state has yet to emerge. In this paper, we will propose the first verifiable structure by improving an existing threshold QSTS scheme. Our scheme has three merits: 1) it is easily realized in physical experiment because only the simple oneparticle unitary operations were involved; 2) each dishonest behavior of one participant could be detected by the next client; and 3) the private key of the dealer could be reused for many times.
Abstract Threshold quantum secret sharing is a typical method for quantum secret sharing (QSS) schemes. In this paper, we propose a verifiable t , n threshold QSS scheme based on the d -dimensional Bell state and asymmetric binary polynomial. In this scheme, the dealer encodes the secret using the asymmetric binary polynomial and generates the corresponding secret share for each participant. Then, the dealer prepares the d -dimensional Bell state, and the participants perform corresponding unitary operations on the particles in transmission to recover the secret. With the hash function and the session key pairs, not only the cheating behavior of the dishonest participants can be detected, but also the specific cheaters can be identified. Furthermore, we consider the case when no less than t participants cooperate to recover the secret, which makes the proposed scheme more practical. Analyses show that the scheme can resist forgery attack, collusion attack and other common attacks.
Abstract Threshold quantum secret sharing is a cryptography technique for dividing and reconstructing secret information. The dealer shares a secret based on quantum mechanics principles, and a subset of participants cooperate to recover that secret. For example, in k , n quantum threshold scheme and n , n quantum threshold scheme, the former can only reconstruct the secret when at least k shares are collected. The latter requires all n shares to be collected to reconstruct the secret. However, in real scenarios, the priority of participant identities may vary. In order to meet the actual needs of participants with different rights, this paper proposes a w , ω , n quantum secret sharing (QSS) scheme. When the sum of participants’ weights w is greater than or equal to a threshold ω, they can cooperate to reconstruct the secret. In order to achieve this, this paper uses the entangled state of single particles and constructs a verifiable QSS scheme based on the Chinese remainder theorem. Significantly, in case of a dishonest participant, the dealer can delete the participant before recovering the secret to ensure the security of the communication. This scheme is more flexible than other threshold protocols. At the same time, it reduces the communication cost of the participants. In addition, security analysis shows that the scheme resists typical external and internal attacks.
Quantum state sharing (QSTS) plays an important role in transporting, managing, and distributing keys. In this paper, by adopting the linear equation instead of using the Lagrange interpolation, a new idea of constructing (t, n) threshold quantum state sharing scheme is proposed. The best innovation is that a new tool in constructing (t, n) threshold structure is proposed. In this scheme, the dealer who possesses a sequence of one-particle unknown quantum states intends to share it with n participants and authorizes t out of them cooperate to reconstruct the sequence. First, the equations decided by the private key of dealer are constructed. Second, the dealer distributes the private keys of n participants by using the solutions to the equations just mentioned. Finally, the dealer encodes the sequence through a unitary operation, and any t out of the n participants recover the initial quantum state sequence through the unitary operations decided by the solutions to the linear equations. Compared to the existing schemes, the proposed scheme is easily realized in physical experiment, and its successful probability is 100% theoretically.
Quantum secret sharing holds a significant place in quantum cryptography. In this paper, a (w, t, n)-weighted threshold dynamic quantum secret sharing scheme with cheating identification is constructed based on the CRT for a polynomial ring. In our scheme, on the premise of not altering the private shares of the old participants, the dynamic update of the participants can be realized without other participants’ help, and the shared secret will not be changed. During the secret reconstruction phase, via executing the quantum state digital signature, the proposed scheme not only can timely detect the existence of the cheating behavior, but also once exists, definitely can identify one cheater and eliminate him from the system, making the scheme more secure. Moreover, our scheme enables secret sharing among participants with different authorities, which enhances the practicability of the scheme. Finally, the security analysis shows our scheme not only is resistant to a range of typical external attacks but can detect forgery, collusion, denial and dishonest revoked participant attacks.