Doc ID024209 Rev 2

21/30

AN4240

Application demo results

6

Application demo results

To better understand the differences between the two cipher modes the following figures will

show an ECB encryption and a CBC encryption starting from the same image:

Figure 16. Demo Starting point

Figure 16 shows that the ECB encryption should not be suggested for encryption of

message with a low variance because, for the same nature of the algorithm, identical

plaintext blocks of messages are encrypted into identical ciphertext blocks. This does not

hide the data pattern well. In some sense it does not provide a high level of confidentiality

and security.