IN YOUR OWN WORDS PLEASE explain

Padding may not always be appropriate. For example, one might wish to store the encrypted data in the same memory buffer that originally contained the plaintext. In that case, the cipher text must be the same length as the original plaintext. A mode for that purpose is the cipher text stealing (CTS) mode. Figure 6.12 a shows an implementation of this mode.

a. Explain how it works.

b. Describe how to decrypt C_n-1 and c_n.