Controlled bidirectional quantum secure direct communication.

Area of Science:

• Quantum Information Science
• Quantum Communication Security

Background:

• Existing quantum communication protocols face challenges with security and controlled access.
• Bidirectional quantum communication requires robust mechanisms to prevent eavesdropping and ensure synchronized information exchange.

Purpose of the Study:

• To propose a novel protocol for controlled bidirectional quantum secure communication.
• To enhance security and efficiency in quantum information exchange between legitimate users.
• To prevent unauthorized access and ensure fair participation through a controller mechanism.

Main Methods:

• Implementation of a nonlocal swap gate scheme.
• Introduction of a controller (Charlie) to manage and authorize quantum information exchange.
• Designing a protocol to prevent information leakage during bidirectional communication.

Main Results:

• The proposed protocol ensures secure bidirectional quantum communication.
• The controller can manage communication without accessing secret information.
• The protocol prevents scenarios where one user receives information before the other, ensuring synchronized exchange.
• The cost of transmitting quantum bits is reduced compared to existing methods.

Conclusions:

• The nonlocal swap gate scheme provides a secure foundation for controlled quantum communication.
• The protocol effectively protects against external and participant attacks.
• This approach offers a cost-effective and secure solution for bidirectional quantum information exchange.