Perfectly secure steganography: hiding information in the quantum noise of a photograph
This addresses the long-standing challenge of perfectly secure steganography for secure communication, representing a foundational advance rather than an incremental improvement.
The paper tackles the problem of achieving information-theoretic secure steganography by hiding secret messages in the quantum noise of photographs, resulting in a protocol where embedded messages are perfectly indistinguishable from ordinary photographs, making it fundamentally impossible to detect private communications.
We show that the quantum nature of light can be used to hide a secret message within a photograph. Using this physical principle we achieve information-theoretic secure steganography, which had remained elusive until now. The protocol is such that the digital picture in which the secret message is embedded is perfectly undistinguishable from an ordinary photograph. This implies that, on a fundamental level, it is impossible to discriminate a private communication from an exchange of photographs.