Question

Using the encryption algortithm that you created in the last activity, hide your message in a picture!

Step 1: Start by creating your own pixel picture! A few things to note when using the color encoding editor:

Each line encodes one pixel, which is one square in the grid.
The editor fills in the grid row by row, going left to right and ignoring any spaces in your code.
Once one row is filled in, the next line of code encodes the first pixel on the next row.
You can use the color picker to choose a color. Then, copy and paste the hexadecimal value under “Key” into the code editor.
Step 2: Change the hexadecimal values just slightly to hide the encrypted message you developed in the previous activity. This will take some exploring! You will probably need to play around with the hexadecimal values to determine which numbers you can adjust without changing the color.

Step 3: Finally, once you’ve determined the best course of action, take note of your encryption process: what values are you changing for which pixels? You will need to add this to your encryption algorithm as the final step in the next activity.

Answer 1

The question involves using steganography to embed an encrypted message into a pixel picture by subtly changing the hexadecimal values of the pixels to include the message without altering the appearance of the image significantly.

Step-by-step explanation:

The question refers to a technique called steganography, which is the practice of hiding a message within another medium, such as a digital image. The term encryption often relates to coding a message in such a way that only authorized parties can decipher it, but here it also involves embedding that message into picture pixels. Each pixel in an image is represented by a hexadecimal value that determines its color. In Step 1, you create a basic pixel picture, each line of code representing a pixel in a row. In Step 2, to hide your encrypted message, you modify the hexadecimal values of those pixels just enough so the color change is imperceptible to the human eye. Finally, in Step 3, you document the encryption process by noting which hexadecimal values you've adjusted. This becomes part of your encryption algorithm, which is a set of steps to encode and decode messages.