The data authentication algorithm, described in Section 12.6, can be defined as using the cipher block chaining (CBC) mode of operation of DES with an initialization vector of zero (Figure 12.7). Show that the same result can be produced using the cipher feedback mode.

= Time 2 Time = N - 1 Time = N Time 1 Di (64 bits) D2 N-1 DN DES encrypt K DES encrypt K (56 bits) K DES encrypt K DES encrypt 01 (64 bits) 02 ON_1 ON DAC (16 to 64 bits)