Electronic Codebook (ECB)

ECB is a block mode of operation# from #Data Encryption Standard (DES) and #Advanced Encryption Standard (AES) where each block of plaintext bits is encoded using Substitution# independently# with the same key. The formal equation for the encryption is as follow:

$$ C_i = \text{ des}_{k1} (p_i) $$

Where:

$C$ is the ciphertext
$\text{des}$ denotes #Data Encryption Standard (DES) algorithm
$k$ is the key
$p$ is the plaintext

If the message is aligned with message block, especially with data such as graphics or with messages the has insignificant change, message repetitions may show in ciphertext. This could cause a code-book analysis problem. It is due to the independence of the ciphertext blocks between each another.

It is typically used for secure transmission or distribution# of single values such as secret keys.

Links to this page

TAC3121 Chapter 5: Symmetric Cryptography

Electronic Codebook (ECB)
Data Encryption Standard (DES)

Electronic Codebook (ECB)#
Cipher Block Chaining (CBC)

However, CBC is a rather slow algorithm compare to Electronic Codebook (ECB) since the block can’t be computed in parallel. In terms of security, the attacker could utilise the CBC nature of using ciphertext as the input for the XOR of the next plaintext, and obtain some information about the next ciphertext.