Implementing-cryptography-using-python

Chapter 6 ■ Using Cryptography with Images 173
print()
print('The image has now been decrypted. Review d_ch6_secret_image.jpg')
fo = open("Chapter6\d_ch6_secret_image.jpg", "wb")
fo.write(image)
fo.close()
While the image is now unreadable, it may also throw an error depending
on the software you are using (see Figure 6.2). This isn’t a showstopper, though,
as you can still email the file anywhere and you will not have to worry about
someone decrypting it without the key, which in this case is 42.
Figure 6.2: Error message for e_ch6_secret_image.jpg
Decrypting will reproduce the image without data loss, as shown in Figure 6.3.
This is important to examine as some modes will have some loss. The image
on the left is the original, while the image on the right has been encrypted and
then decrypted. Later, we will examine various encryption modes that work
well on regular files but fail on images. One such example is the use of the ECB
mode discussed shortly.
In the next section, we will start exploring more complex solutions using
cryptographic libraries.