Which technique encodes secret information by substituting insignificant bits with the secret message?

Which technique encodes secret information by substituting insignificant bits with the secret message?

• A. Transform Domain Techniques
• B. Spread Spectrum Techniques
• C. Distortion Techniques
• D. Substitution Techniques

Answer: (D)

Substitution of the least significant bits is a steganographic method where the secret message is hidden by replacing the least significant bits of the cover data with the message bits. Because those trailing bits carry minimal perceptual information in formats like images or audio, changes to them are usually imperceptible to humans, allowing the hidden data to be extracted later by reading those same bits back out. This approach is straightforward and efficient for embedding, which is why it’s commonly described as a substitution technique. This differs from transform-domain techniques, which hide data by altering coefficients in a transformed space (like frequency components in images). It also contrasts with spread-spectrum techniques, which conceal the message by distributing it across a wide range of frequencies, and with distortion techniques, which encode information by modifying the cover in a way that affects its quality or structure. The substitute-bit method is simple and effective for small to moderate payloads, but it can be more vulnerable to detection and data loss if the cover is altered or analyzed aggressively.

Substitution of the least significant bits is a steganographic method where the secret message is hidden by replacing the least significant bits of the cover data with the message bits. Because those trailing bits carry minimal perceptual information in formats like images or audio, changes to them are usually imperceptible to humans, allowing the hidden data to be extracted later by reading those same bits back out. This approach is straightforward and efficient for embedding, which is why it’s commonly described as a substitution technique.

This differs from transform-domain techniques, which hide data by altering coefficients in a transformed space (like frequency components in images). It also contrasts with spread-spectrum techniques, which conceal the message by distributing it across a wide range of frequencies, and with distortion techniques, which encode information by modifying the cover in a way that affects its quality or structure. The substitute-bit method is simple and effective for small to moderate payloads, but it can be more vulnerable to detection and data loss if the cover is altered or analyzed aggressively.