Composable security of CV-MDI-QKD with secret key rate and data processing

Area of Science:

• Quantum Information Science
• Quantum Cryptography
• Quantum Communication Security

Background:

• Continuous-variable quantum key distribution (CV-QKD) offers enhanced security over classical methods.
• Measurement-device-independent (MDI) protocols eliminate vulnerabilities associated with imperfect measurement devices.
• Finite-size effects and composable security are critical for practical quantum key distribution (QKD) implementation.

Purpose of the Study:

• To provide a rigorous security proof for continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD).
• To incorporate finite-size effects and composable security terms into the proof.
• To validate the protocol's practical feasibility through realistic simulations.

Main Methods:

• Development of a security proof for CV-MDI-QKD.
• Inclusion of finite-size analysis and composable security definitions.
• Implementation of protocol simulations using a dedicated Python library.

Main Results:

• A rigorous security proof for CV-MDI-QKD with finite-size and composable security was established.
• Simulations demonstrated that the protocol can achieve results close to experimental expectations.
• The Python library facilitated the simulation of all protocol stages, from quantum communication to key extraction.

Conclusions:

• The presented security proof and simulations confirm the viability of CV-MDI-QKD for practical secure communication.
• The study highlights the importance of considering finite-size effects and composable security for real-world QKD systems.
• The developed simulation framework provides a valuable tool for optimizing and validating future quantum key distribution protocols.