A scheme is proposed by which two parties, Alice and Bob, can securely exchange real numbers. The scheme requires Alice and Bob to share entanglement and both to perform Bell-state measurements. With a qubit system two real numbers can each be sent by Alice and Bob, resulting in four real numbers shared by them. The number of real numbers that can be shared increases if higher-dimensional systems are utilized. The number of significant figures of each shared real number depends upon the number of Bell-state measurements that Alice and Bob perform. The security of the scheme against individual eavesdropping attacks is analyzed and the effects of channel losses and errors discussed.
A scheme is proposed by which two parties, Alice and Bob, can securely exchange real numbers. The scheme requires Alice and Bob to share entanglement and both to perform Bell-state measurements. With a qubit system two real numbers can each be sent by Alice and Bob, resulting in four real numbers shared by them. The number of real numbers that can be shared increases if higher-dimensional systems are utilized. The number of significant figures of each shared real number depends upon the number of Bell-state measurements that Alice and Bob perform. The security of the scheme against individual eavesdropping attacks is analyzed and the effects of channel losses and errors discussed.
A quantum key distribution protocol, based on the quantum dense encoding in entangled states, is presented. In this protocol, we introduce an encoding process to encode,two classical bits information into one of the four one-qubit unitary operations implemented by Alice and the Bell states measurement implemented by Bob in stead of direct measuring the previously shared Einstein-Podolsky-Rosen pairs by both of the distant parties, Alice and Bob Considering the practical application we can get the conclusion that our protocol has some advantages. It not only simplifies the measurement which may induce potential errors, but also improves the effectively transmitted rate of the generated qubits by the raw key. Here we also discuss eavesdropping attacks against the scheme and the channel loss.
A scheme is proposed for quantum information splitting of a two-qubit Bell state by using a four-qubit entangled state as a quantum channel. In the scenario, it is supposed that there are three legitimate parties, say Alice, Bob and Charlie. Alice is the sender of quantum information. Bob and Charlie are two agents. Alice first performs GHZ state measurement and tells Bob and Charlie the measurement results via a classical channel. It is impossible for Bob to reconstruct the original state with local operations unless help is obtained from Charlie. If Charlie allows Bob to reconstruct the original state information, he needs to perform a single-qubit measurement and tell Bob the measurement result. Using the measurement results from Alice and Charlie, Bob can reconstruct the original state. We also consider the problem of security attacks. This protocol is considered to be secure.
A scheme of two-way teleportation is proposed,with Bell entangled state as Quantum Channel(QC).Firstly,two sides of communication(Alice and Bob),share two EPR entangled states.After communication,Alice and Bob perform Bell-state joint measurements to their own qubits respectively,and announce the measured results via Classical Channel(CC).Then according to the measured results,Alice and Bob make relevant unitary transformations,namely,its own party can reproduce the opposite quantum state information,and thus the two-way teleportation is realized.In order to enhance the security of two-way teleportation,and the analysis result indicates that the system′s security will strengthen with the increase of the control particles,but the security will not strengthen when the control particles increase to a certain number.
This paper proposes a novel distributed key generation scheme based on quantum entanglement, aiming to achieve fully secure key distribution without prior key exchange. The core concept leverages quantum entanglement between two or more nodes to generate and transmit keys, combined with a quantum key distribution protocol for verification and error correction. Unlike existing quantum key distribution schemes reliant on quantum communication channels, this approach offers a theoretically more secure and potentially efficient method for key sharing. The system utilizes Bell states, polarization measurements, and post-processing techniques to establish a shared key. We outline the key components of the system, including entanglement generation, measurement protocols, error correction, and key distillation. The theoretical analysis demonstrates the security of the scheme against eavesdropping attacks, assuming the validity of quantum mechanics. This work contributes to the ongoing research in quantum cryptography and provides a foundational design for a future generation of secure communication networks.
This paper proposes a novel distributed key generation scheme based on quantum entanglement, aiming to achieve fully secure key distribution without prior key exchange. The core concept leverages quantum entanglement between two or more nodes to generate and transmit keys, combined with a quantum key distribution protocol for verification and error correction. Unlike existing quantum key distribution schemes reliant on quantum communication channels, this approach offers a theoretically more secure and potentially efficient method for key sharing. The system utilizes Bell states, polarization measurements, and post-processing techniques to establish a shared key. We outline the key components of the system, including entanglement generation, measurement protocols, error correction, and key distillation. The theoretical analysis demonstrates the security of the scheme against eavesdropping attacks, assuming the validity of quantum mechanics. This work contributes to the ongoing research in quantum cryptography and provides a foundational design for a future generation of secure communication networks.
We study the problem of secret key distillation from bipartite states in the scenario where Alice and Bob can perform measurements only at the single-copy level and classically process the obtained outcomes. Even with these limitations, secret bits can be asymptotically distilled by the honest parties from any two-qubit entangled state, under any individual attack. Our results point out a complete equivalence between two-qubit entanglement and secure key distribution: a key can be established through a one-qubit channel if and only if it allows one to distribute entanglement. These results can be generalized to a higher dimension for all those states that are one-copy distillable.