Continuous-Variable Quantum Network Coding Against Pollution Attacks

Abstract

Continuous-variable quantum communication protocols have gained much attention for their ability to transmit more information with lower cost. To break through the bottleneck of quantum network coding schemes, continuous-variable quantum network coding (CVQNC) schemes were proposed. In spite of network throughput improvement, CVQNC also brings on security problems such as pollution attacks, in which case errors are accumulated and spread to all downstream nodes. In this paper, we propose a continuous-variable quantum network coding scheme with quantum homomorphic signature to resist pollution attacks. The scheme utilizes pre-shared quantum entanglement and classical communication to implement perfect crossing transmission of two quantum states. By combining two quantum signatures of classical messages generated by source nodes, the scheme will generate a homomorphic signature, which is used to verify the identities of different data sources in a quantum network. Security analysis shows the proposed scheme is secure against forgery and repudiation.