Скачать или смотреть AES-CBC with random data - ESP32 + SX1278 LoRa

Demonstration app of AES block cipher, especially AES-CBC mode of operation. Used with random data generation on the LoRa transmitter side. These datas are GPS credentials and one byte value. Transmitter is also generating Initialization Vector (IV) by its internal true random number generator.

Transmitter is transmitting initialization vector in plaintext (16 bytes) and ciphertext (32 bytes). Transmitter and receiver has AES encryption / descryption key stored in their firmware. There is used 256-bit AES key wihin the application.

Receiver is using initialization vector in decryption operation, as its user within a algorithm for XOR operation with the first block and also other blocks are XORed with blocks next to them, visit AES-CBC description on Wikipedia for better insight.

Program implementation is in Arduino Core, transmission for LoRa PPP is made using Arduino_LoRa library. All cryptographic functions are from mbedTLS library that is inbuilt directly in Arduino Core or ESP-IDF framework. In the firmware there are more things done, such as padding and unpadding of the data for 16 bytes blocks using PKCS#7 method.

On the transmitter side I have used ESP32-WROOM-32. On receiver side I have used ESP32-C6. LoRa modules in this case were SX1278 (RA-02) which were operating on 433 MHz. This firmware is also compatible with SX1276 or similar. So 868 MHz and 915 or 923 MHz bands are supported too!

For the program implementation please visit: https://github.com/martinius96/AES-CB...

Static data sending demonstration with AES-CBC:    • AES-CBC encryption - ESP32 + LoRa SX1278 (...  

Article (Slovak language only): https://deadawp.blog.sector.sk/blogcl...