6G Single‐Pixel Meta‐Encryption with Ultra‐Robustness

ABSTRACT As a promising carrier for 6G communication, terahertz waves are particularly susceptible to eavesdropping and transmission sabotage during wireless propagation. However, the existing terahertz encryption schemes are challenging to intrinsically protect the wireless transmission, whose encryption systems are also bulky and hard to integrate. Here, to meet the requirement of confidential 6G wireless links, we propose a single‐pixel meta‐encryption scheme based on statistical optics empowered Hadamard metasurfaces, which can achieve strong security, key tolerance, and ultra‐robustness. The metasurfaces are prepared by 3D printing technology for simple, rapid, and low‐cost fabrication. By modulating terahertz waves with Hadamard metasurfaces and combining single‐pixel imaging, the scheme achieves a key space size of 10 90 and 31% key tolerance. Experimental results show that even if 97% of the optical path is severely blocked or there are 30% errors in the key, the transmitted images can be reconstructed. Our approach combines single‐pixel imaging with terahertz metasurfaces to address security challenges in future wireless communication, paving the way for secure, robust, and efficient encryption frameworks applicable to communication networks from 6G to XG.