Multi-Channel Secret Sharing and Camouflage in Programmable Metasurface-Based Wireless Communication

Information security has become increasingly critical with the widespread development of wireless technologies. However, current information security technologies predominantly rely on either software-layer or physical-layer encryption as standalone solutions, both of which present fundamental constraints. In this article, a novel architecture for multi-channel secret sharing and camouflage is proposed by combining both software- and physical-layer security mechanism based on a programmable metasurface. At the software layer, a one-time pad (OTP) algorithm employs exclusive-OR (XOR) operations with dynamic keys and predefined camouflage data to encrypt and share secrets. At the physical layer, the programmable metasurface spatially disperses the shared messages through reconfigurable multi-beam steering and polarization control. Over-the-air experiments demonstrate that the proposed architecture successfully realizes dynamic OTP secret sharing, a capability unattainable with static metasurface-based systems. The robustness of the system is also verified, underscoring its potential for real-world applications. Crucially, legitimate users must collaboratively combine all distributed keys and encrypted messages for secret recovery, whereas eavesdroppers intercepting individual channels obtain only non-decryptable fragments, which correspond to predefined camouflage data. This work synergistically integrates software-layer encryption with the physical-layer functionalities of programmable metasurfaces, offering transformative potential for future highly secure wireless networks and distributed data storage architectures.