kilobyte, the number of bits that may be changed is given by the
total number of least significant bits available (one bit from each
byte) divided by the number of bits required for one text character (we
consider 8 bits). Therefore, 1 kilobyte of image file can accommodate
1024/8 bits = 128 bytes. Hence, a text file of 128 bytes could be hidden
in a bit-mapped image of 1 kilobyte.
1. Login to a Windows machine in the lab.
a. Username: Administrator
b. Password: (no password)
2. Double click the “Steganography” link on the desktop.
3. Click on Open Jpeg on the menu bar and open a file in the My
Pictures folder in My Documents.
4. Create any text file “hello.txt” with some text in the My
Pictures folder.
5. Click on Hide on the menu bar and give a password “hide” and
reenter as required. Then point to the file “hello.txt” that you intend
to hide. And lastly, save the image as “hidden.jpg” in the My Pictures
folder.
6. Close all open files. The message text in “hello.txt” has
been hidden in the jpeg image file “hidden.jpg”
7. Now to retrieve the hidden message, open the file
“hidden.jpg” and give the password as necessary.
8. Click on Seek on the menu bar
9. Save the file as hidden “retrieved.txt” into the My Pictures
folder; replace if necessary.
10. Is the message the same in “hello.txt” and “retrieved.txt”
?
11. What other types files be used to hide text data using
stenography?
12. What are possibly some useful uses of stenography?
13. Close all windows.
