3.1 The PRINCE cipher
PRINCE operates on 64-bit blocks and uses a 128-bit key k which composed of two 64-bits elements, k0 and k1.
It is based on the so-called FX-construction. The 128-bit key is extended to 192 bits by the mapping: (k0jjk1)!
(k0jjk0
0 jjk1)=(k0jj(k0o1)(k063)jjk1). k0 and k0
0 are used as whitening keys, while k1 is the 64-bit key used
without updates by the 12-round block cipher refer to as PRINCEcore. The whole encryption process of PRINCE
is depicted in Figure 1.