Image Steganography for High-Bandwidth Covert Communication on Ethereum Election Contracts

Abstract

The exponential growth of connected devices and embodied intelligent systems in B5G and 6G networks demands secure, adaptive, and autonomous communication among distributed agents. However, ensuring privacy-preserving coordination among these Agentic AI systems remains a major challenge, particularly in decentralized environments where transparency conflicts with confidentiality. To address this issue, we propose a Smart-contract-based Embodied Covert Agent Communication Architecture (SECA), which integrates Ethereum election contracts with image steganography to enable covert, high-bandwidth communication among intelligent agents. In this framework, Blockchain-based agents utilize candidate images as visual carriers to embed encrypted messages, achieving imperceptible data exchange during on-chain interactions. We further design a Stackelberg Minimal Control Algorithm (SMCA) that enables adaptive manipulation of voting agents to ensure communication reliability with minimal control cost. Experimental results demonstrate that our approach achieves a transmission bandwidth up to 103× higher than ORIM-based covert channels and passes multiple detection benchmarks (K-S and χ2tests), all without incurring additional gas costs. This work provides a foundational perspective for secure Agentic AI communication frameworks, bridging embodied intelligence, decentralized networking, and covert information transmission in emerging 6G environments.