The main purpose of the sharing schemes based on trusted servers is to obtain a password. The threshold cryptography aims the secret cryptographic protection, and is based on the distribution of the key on several servers, with the purpose to tolerate the attacks. In this work I will present a quantum version of the password sharing protocol, using a number n of trustful servers, to assure its security. The model I propose approaches the issue of the distribution of the authentication key between a client and n-1 servers.
The main purpose of the sharing schemes based on trusted servers is to obtain a password. The threshold cryptography aims the secret cryptographic protection, and is based on the distribution of the key on several servers, with the purpose to tolerate the attacks. In this work I will present a quantum version of the password sharing protocol, using a number n of trustful servers, to assure its security. The model I propose approaches the issue of the distribution of the authentication key between a client and n-1 servers.
A theoretical scheme for multi-user quantum authentication and key distribution in a network is proposed. Similar to the authentication architecture of the netw ork in classical cryptography, a distributed client/server architecture with the shared Einstein-Podolsky-Rosen(EPR) entangled pairs between each user and his t rusted server used for the authentication and key distribution is proposed. Base d on this architecture, any-to-any multi-user quantum authentication and key dis tribution is realized. The trusted server only provides the authentication betwe en users and swaps the entanglement between the particles so as to entangle the particles of the two users who want to communicate secretly. The key generation is performed by the requesting user. Each user in a network only shares Einstein -Podolsky-Rosen entangled pairs with the trusted server and communicates with th e trusted server through the classical channel and quantum channel. Users need n ot share EPR entangled pairs with each other so that the number of EPR pairs in the network is reduced from O(n2) to O(n).
In this paper, we design an ID-based M-server quantum password-authenticated key exchange scheme, where the client computes a strong key from its password and splits the key into m portions, and then encrypts them and sends them to m servers to be used as the basis for encryption and decryption in the subsequent key exchange process. The adoption of multiple servers can effectively prevent third-party attacks on the server and ensure the security of the key information, which is just like a complex secret sharing mechanism in traditional computational cryptography, for example, secret sharing (m, n) threshold scheme, but our new quantum fusion technology to realise the secret sharing mechanism is more efficient and simpler. Finally, through analysis, our scheme can meet most of the security requirements and perform well. It is feasible to implement the protocol under the existing quantum technology.
In this paper, we design an ID-based M-server quantum password-authenticated key exchange scheme, where the client computes a strong key from its password and splits the key into m portions, and then encrypts them and sends them to m servers to be used as the basis for encryption and decryption in the subsequent key exchange process. The adoption of multiple servers can effectively prevent third-party attacks on the server and ensure the security of the key information, which is just like a complex secret sharing mechanism in traditional computational cryptography, for example, secret sharing (m, n) threshold scheme, but our new quantum fusion technology to realise the secret sharing mechanism is more efficient and simpler. Finally, through analysis, our scheme can meet most of the security requirements and perform well. It is feasible to implement the protocol under the existing quantum technology.
Recently, Yang et al. proposed a kind of quantum cryptographic schemes based on secret sharing. The main idea is drawn from the case, where any n participants who share a secret K can co-operate as K does. This process can be applied to encryption, authentication, signature and so on. Unfortunately, since there is no identity authentication of the share’s holder, these schemes inherit the limitation of secret sharing in practice. If some participants do not follow the protocol, the protocol would be a failure at last. Moreover, these schemes encounter another serious attack. Any two participants can co-operate to defeat the schemes by sending different shares to the parties unknown to the distributor of the secret K, such that these parties can execute the protocol as well. The attack proves that it is not enough for quantum cryptographic schemes that only the secret key is secure.
In quantum cryptography, quantum secret sharing (QSS) is a fundamental primitive. QSS can be used to create complex and secure multiparty quantum protocols. Existing QSS protocols are either at the (n,n) threshold 2 level or at the (t,n) threshold d level with a trusted player, where n denotes the number of players and t denotes the threshold number of players. Here, we propose a secure d-level QSS protocol for sharing a secret with efficient simulation. This protocol is more secure, flexible, and practical as compared to the existing QSS protocols: (n,n) threshold 2-level and (t,n) threshold d-level with a trusted player. Further, it does not disclose any information about the secret to players. Its security analysis shows that the intercept-resend, intercept, entangle-measure, forgery, collision and collusion attacks are not possible in this protocol.
Abstract Secret sharing, as an important cryptographic technique, effectively reduces the risk of single points of failure and centralized leakage by distributing secret information across multiple independent entities. With the widespread application of cloud computing and cloud storage, achieving long-term secure storage and controllable recovery of sensitive data in untrusted cloud environments has become a critical issue. Traditional cloud storage solutions face potential risks of security degradation and privacy exposure under long-term operation and future quantum computing threats. This paper proposes a quantum secret sharing (QSS) scheme for cloud storage scenarios, combining the threshold secret sharing with quantum secure communication and quantum information processing to achieve distributed storage and secure reconstruction of secret information across multiple cloud servers. A quantum identity authentication mechanism is introduced to the authenticated user based on a quantum sequence. This protocol enhances the long-term security of the system during the storage phase through threshold distribution and proactive share refreshing mechanisms, and utilizes quantum states to complete the secure reconstruction of secrets during the recovery phase. Additionally, this scheme avoids direct interaction between cloud servers, improving the security in untrusted cloud environments. Security analysis shows that this protocol can effectively resist threats such as external eavesdropping and internal collusion.