Polar Coding for Confidential Broadcasting

Area of Science:

• Information Theory
• Coding Theory
• Cybersecurity

Background:

• Wiretap Broadcast Channel (WBC) security is crucial for multi-user communication.
• Existing polar coding schemes for WBCs have limitations in multi-receiver scenarios.
• Securely transmitting identical confidential messages to multiple legitimate receivers is an open challenge.

Purpose of the Study:

• To propose a polar coding scheme for a WBC with two legitimate receivers and one eavesdropper.
• To enable reliable and secure transmission of the same confidential message to both receivers.
• To achieve optimal randomness rate without channel symmetry or degradedness assumptions.

Main Methods:

• Development of a new polar coding chaining construction.
• Analysis of dependencies between random variables in the coding scheme.
• Secrecy analysis considering the new construction's impact.

Main Results:

• The proposed scheme allows reliable and secure transmission of a confidential message to two legitimate receivers.
• The scheme achieves optimal randomness rate.
• The new chaining construction introduces novel dependencies affecting secrecy analysis.

Conclusions:

• The novel polar coding chaining construction effectively addresses secure multi-receiver communication in WBCs.
• This work advances the application of polar codes in wiretap channel scenarios.
• Further analysis is needed to fully characterize the secrecy performance under the new dependencies.