Introduction to Image Steganography Answers 1. What is the primary goal of image steganography? A. To encrypt messages to keep them secret B. To make the hidden information imperceptible to the naked eye C. To increase the size of digital files D. To improve the quality of digital images Answer: To make the hidden information imperceptible to the naked eye (B) Image steganography focuses on concealing secret information within a digital image in a way that makes it undetectable. 2. Which method is commonly used to embed secret messages in images by altering pixel data? A. Pixel Value Modification B. Least Significant Bit (LSB) Modification C. Image Compression Methods D. Transform Domain Methods Answer: Least Significant Bit (LSB) Modification (B) Least Significant Bit (LSB) Modification is a widely utilized method for embedding messages by altering the least significant bits of image pixels. 3. What is an advantage of Transform Domain Methods in image steganography? A. They do not require any alterations to the image B. They are immune to image degradation C. They are simpler to implement than LSB methods D. They provide better quality results for larger messages Answer: They provide better quality results for larger messages (D) Transform Domain Methods, such as DCT or DWT, yield better quality when hiding larger or more complex messages. 4. Which of the following is a major concern when embedding messages in images? A. The imperceptibility of the hidden message B. The speed of message retrieval C. The file format of the image D. The color balance of the image Answer: The imperceptibility of the hidden message (A) Imperceptibility is crucial in steganography; the hidden message should not be visually discernible. 5. What challenge does perceptual masking present in image steganography? A. It allows for better compression of the images B. It makes messages easier to detect C. It decreases the capacity for hidden data D. It makes it hard to hide information without noticeable changes Answer: It makes it hard to hide information without noticeable changes (D) Perceptual masking makes it challenging to hide information in a way that remains unnoticed by the human eye. 6. Which method involves exploiting redundancies in image data sets? A. Least Significant Bit (LSB) Modification B. Spread Spectrum Techniques C. Image Compression Methods D. Pixel Value Modification Answer: Image Compression Methods (C) Image Compression Methods can hide secret information by exploiting redundancies in the image's data. 7. What is a limitation of methods that rely on image processing? A. They are too complex for practical use B. They may diminish the quality or recoverability of the hidden message C. They offer a higher capacity for hidden messages D. They can enhance the quality of the hidden message Answer: They may diminish the quality or recoverability of the hidden message (B) Methods that involve processing may affect the hidden message, risking its quality and recoverability. 8. In steganography, what does robustness refer to? A. The ability of the message to survive image manipulations B. The speed of embedding messages C. The size of the digital image used D. The ease of detecting hidden messages Answer: The ability of the message to survive image manipulations (A) Robustness is the ability of the embedded message to withstand alterations such as compression and resizing.