ABSTRACT
The implementation of any block cipher algorithm depends on the mode of operation, which governs the relation between blocks during the encryption process. The ECB mode is one of the possible modes of operation. In this mode, each block is encrypted independently. Unlike different modes of operation, this mode allows parallel processing, which is a great advantage. Unfortunately, because the encryption of each block does not depend on other blocks, an adversary can replace any block with a previously intercepted block without detection; hence, the message is hacked without the need to know the key. This major security problem is called the block independency problem. In addition, identical plaintext blocks are encrypted to identical ciphertext blocks, so symmetrical large data patterns, like those in images, cannot be hidden using any encryption algorithm implemented in the ECB mode [98-102].
