Quantum technique hides secret messages in phase shifts of signals
A Novel Steganography Scheme Using Quantum Hilbert Transform
Cryptography and SecurityInformation Theory
Summary
Steganography is about hiding secret messages inside everyday communication so no one notices. The authors explore a new way to hide information using quantum computers, focusing on subtle changes in the phase, which is like a hidden angle in a quantum signal. They develop a mathematical tool called the Quantum Hilbert Transform to embed bits of information as tiny phase changes in quantum states. To retrieve the secret message, the receiver uses special quantum measurements along with classical error correction methods to accurately decode the hidden bits.
SteganographyQuantum Hilbert TransformPhase domainQuantum Fourier TransformQuantum statesUnitary operatorBinary state discriminationError-correcting codes
Authors
Nitin Jha, Abhishek Parakh
Abstract
The main goal of steganography is to transmit hidden messages in legitimate-looking communication messages. Phase-domain information hiding, however, has not been fully explored for quantum systems. This work introduces a finite-dimensional Quantum Hilbert Transform (QHT) as a unitary phase operator based on the Quantum Fourier Transform. Using this construction, we develop a QHT-based quantum steganography scheme that embeds classical bits as weak signed phase perturbations of quantum cover states. Bob recovers the hidden message through binary state discrimination, block aggregation, and classical error-correcting decoding.