Which of the following DES modes is typically used when small amounts of data are encrypted, such as in ATM PIN numbers?

A.
OFB

B.
ECB

C.
CFB

D.
CBC

Explanation:
Electronic Code Book mode does not use any chaining. This means that
the same plaintext will create the same ciphertext each and every time it is
encrypted with the same key. The other DES modes use chaining, which means some of
the previously encrypted data is used in the encryption process. These modes do not
provide patterns as the ECB mode does.