STMicroelectronics STM32WL5 Series User Manual

RM0453 Rev 5 651/1450
RM0453 AES hardware accelerator (AES)
694
Cipher block chaining (CBC) mode
Figure 103. CBC encryption and decryption principle
In CBC mode the output of each block chains with the input of the following block. To make
each message unique, an initialization vector is used during the first block processing.
Note: For decryption, a special key scheduling is required before processing the first block.
MSv42141V1
Encryption
Plaintext block 1 Plaintext block 2 Plaintext block 3
Ciphertext block 1 Ciphertext block 2 Ciphertext block 3
Encrypt Encrypt Encrypt
Decryption
key key key
Plaintext block 1 Plaintext block 2 Plaintext block 3
Ciphertext block 1 Ciphertext block 2 Ciphertext block 3
Decrypt Decrypt Decrypt
key key key
input
output
key
scheduling
Legend
initialization
vector
initialization
vector

STMicroelectronics STM32WL5 Series Specifications

General

Brand	STMicroelectronics
Model	STM32WL5 Series
Category	Microcontrollers
Language	English