Unlike in symmetric-key cryptography, plaintext and ciphertext are treated as integers
in asymmetric-key cryptography. The message must be encoded as an integer (or a set
of integers) before encryption; the integer (or the set of integers) must be decoded into
the message after decryption. Asymmetric-key cryptography is normally used to
encrypt or decrypt small pieces of information, such as the cipher key for a symmetrickey
cryptography. In other words, asymmetric-key cryptography normally is used for
ancillary goals instead of message encipherment. However, these ancillary goals play a
very important role in cryptography today.