Figure 220. Des/Tdes-Cbc Mode Encryption - ST STM32F405 Reference Manual

RM0090
1. K: key; C: cipher text; I: input block; O: output block; Ps: plain text before swapping (when decoding) or
after swapping (when encoding); P: plain text; IV: initialization vectors.

Figure 220. DES/TDES-CBC mode encryption

DATATYPE
AHB2 data write
(before CRYP
is enabled)
IV0(L/R)
K1
O is written back
into IV at the
K2
same time as it
is pushed into
the OUT FIFO
K3
DATATYPE
RM0090 Rev 18
Cryptographic processor (CRYP)
IN FIFO
plaintext P
P, 64 bits
swapping
Ps, 64 bits
64
+
I, 64 bits
64
DEA, encrypt
64
DEA, decrypt
64
DEA, encrypt
O, 64 bits
swapping
C, 64 bits
OUT FIFO
ciphertext C
ai16070b
727/1749
766