Embedded AES Encryption for Secure FSK-Based Talkative Power Conversion With DC–DC Converters

Talkative Power Conversion (TPC), also known as switching-ripple communication (SRC), provides cost-effective data transmission for smart grids, DC microgrids, and automotive power systems, but it remains vulnerable to unauthorized access and data interception. This paper proposes an integrated TPC system embedding Advanced Encryption Standard 128 (AES-128) encryption directly into a binary frequency shift keying (FSK)-modulated DC-DC buck converter, eliminating external modems and security hardware. The key novelty is a converter-centric physical-layer co-design that seals plaintext within the converter controller and transmits only ciphertext ripple on the shared DC bus without external modem/security interfaces. Utilizing the converter's intrinsic switching ripple for data transmission, the buck converter transmits encrypted data using 61 kHz and 73 kHz switching frequencies, with a 24 kHz synchronization tone. Real-time encryption, modulation, demodulation, and decryption are implemented on a PYNQ-Z2 FPGA board. Experimental validation demonstrates secure, error-free data transmission with desired power quality, confirming the proposed method's practicality. The integrated FPGA-based solution significantly reduces system complexity and cost, ensuring robust protection against cyber threats in DC power distribution systems.