Download the Visual Encryptor program here: VisualEncryptor.exe
If you want to you may use these bitmaps to play around with in the program:
right-click on any image and select "Save Picture As..." to download
- You may view and modify the source code by downloading these files:
- Before you open the workspace, store the file Toolbar.bmp,
in a folder named "res" that is in the same working directory as the the rest of the source files.
- This project was created using Microsoft Visual C++ 6.0.
How to Encrypt an Image Using Visual Encryptor
- Open the secret image .bmp file using either the "Open SI..." command under the
"File" menu or using the Open button in the toolbar.
This adds the selected file to the third combo box in the toolbar, which lists
the files that have been opened or created
- Select the desired Visual Cryptography scheme from the first combo box in the toolbar. You will be
prompted for any information necessary to define the access structure (such as the number
of participants, the threshold, or qualified sets of participants). Details on each of
the schemes are given below.
- Select the desired pixel expansion method from the second combo box in the toolbar.
Detailed information about each pixel expansion method is given below.
- Encrypt the secret image (the image currently displayed will encrypted) either by
selecting "Encrypt" from the "Encrypt" menu or by pressing the Encrypt button
on the toolbar.
The created shares are stored in the files "sharek.bmp" where k
is the number of the participant corresponding to the share. The name of each
share is then added to the third combo box. You can choose which file to display
in the main window by selecting that file from the third combo box (though, only
one file may be displayed at a time).
- You can 'overlay' any set of up to 9 images either by selecting the "Coalesce..."
command from the "Coalesce shares..." menu or by pressing the Coalesce button
on the toolbar.
The overlaid image will be saved as "coalesce.bmp", added to the
third combo box (of viewable files), and displayed as the current image in the main
- Any time you choose "Encrypt", the current image that is displayed in the main
window (and selected in the third combo box) is the image that will be encrypted.
- You may add new filenames to the third combo box by pressing the Open button
on the toolbar or by selecting "Open SI..." from the
- The combo box holds up to 25 viewable files at a time. If a file is opened or created
when the combo box is full, it replaces the last filename in the combobox.
- You can remove any filename from the combo box by selecting it from the combo box and
choosing the "Close" command from the "File" menu.
- You can remove all of the files from the combo box at once by choosing the "Close all"
command from the "File" menu.
- You can save a file under a different name by pressing the Save As button
on the toolbar or by selecting the "Save current as.."
command from the "File" menu. The new filename will replace the old one in the
third combo box.
This feature may be especially useful for renaming the created share images
because every time you choose to "Encrypt" the secret image the newly created
shares will again be stored in "sharek.bmp" and any files previously
stored under those filenames will be overwritten. Similarly, every time you choose
to "Combine shares..." the overlaid image is stored in "coalesce.bmp" and any
image already stored under that filename is rewritten, so it might be useful to
rename the current "coalesce.bmp" before running "Combine shares..." again (else it
will be lost).
- The image you encrypt must be a Windows bitmap file, though it does not have to be a
black and white bitmap. However, the encryption algorithm will assume that any
pixel that is not white is black when it encrypts the secret image.
Access Structure Schemes
Pixel Expansion Methods