Cifradopro: A baremetal Hardware Security Module using the STM32L4S5 Cortex-M4 MCU
What is CifradoPro? Cifradopro is a baremetal Hardware Security Module based on the STM32L4S5ZI microcontroller. It is capable of generating Random Keys in various sizes, Encrypting plaintext, and Decrypting ciphertext using the Advanced Encryption Standard. Additionally, it can create One-Time Pads of different lengths and generate a Hash of input data using the Secure Hashing Algorithm. The module can store the generated cryptographic keys in an external memory device. As a safeguard against physical tampering, the device is designed to erase the contents of the external memory if the enclosure is breached. The device leverages the Random Number Generator , AES Hardware Accelerator , and HASH Processor of the STM32L4S5ZI for cryptographic operations. It employs the built-in UART peripheral for device control via a serial terminal application such as PuTTY. The external memory, a 256kBit EEPROM from Microchip , is interfaced using the STM32L4's onboard I2C Peripheral. A GPIO pin