Which technique relies on pre-negotiated manipulations to reveal messages written with invisible ink?

Which technique relies on pre-negotiated manipulations to reveal messages written with invisible ink?

• A. Technical Steganography
• B. Microdots
• C. Spread Spectrum Techniques
• D. Invisible Ink

Answer: (D)

Invisible ink hinges on a pre-arranged trigger to bring the hidden message into view. The sender and receiver agree in advance how the message will be revealed—such as applying heat, using a specific chemical reagent, or exposing the paper to UV light. Without that agreed manipulation, the writing remains invisible, which is exactly why this technique is used. The other options describe different hiding methods that don’t rely on a known reveal action: technical steganography hides data in digital or physical media and requires a decoding process; microdots store information in tiny images readable with magnification; spread spectrum techniques conceal data by spreading it across frequencies and require the correct receiver parameters to recover it.

Invisible ink hinges on a pre-arranged trigger to bring the hidden message into view. The sender and receiver agree in advance how the message will be revealed—such as applying heat, using a specific chemical reagent, or exposing the paper to UV light. Without that agreed manipulation, the writing remains invisible, which is exactly why this technique is used. The other options describe different hiding methods that don’t rely on a known reveal action: technical steganography hides data in digital or physical media and requires a decoding process; microdots store information in tiny images readable with magnification; spread spectrum techniques conceal data by spreading it across frequencies and require the correct receiver parameters to recover it.