Cipher Block Chaining (Cbc) - ST STM32F413 Reference Manual

Advanced encryption standard hardware accelerator (AES)
24.5.2

Cipher block chaining (CBC)

In cipher-block chaining (CBC) mode, each block of plain text is XORed with the previous
cipher text block before being encrypted. To make each message unique, an initialization
vector (AES_IVRx) is used during the first block processing.
The initialization vector is XORed after the swapping management block during encryption
mode and before it in decryption mode (refer to
684/1284
Figure 226. ECB decryption mode
Figure 227
DocID029473 Rev 3
and Figure 228).
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