Optical encoding is the process of turning digital data into visible patterns that a compatible reader can decode back into bits. The pattern may look like bars, dots, glyphs, or other structured shapes on paper or a screen. The key requirement is that the encoding and decoding rules are precise enough that the original data can be reconstructed later without ambiguity.
In cyber security, optical encoding matters because it can move or preserve data without a conventional electronic file transfer. Defenders use it for offline backups, air-gapped workflows, and recovery media when networked systems are unavailable. Attackers can also abuse visual channels to smuggle data out of restricted environments, hide payloads in images, or bypass controls that inspect only normal file types. The security value depends on durability, error correction, and whether the decoding software and documentation survive with the medium.