AES-GFM

The GFM operation is often used as part of various AES cryptographic operations. This function has been provided to aid in the creation of operations that are not directly supported by the ATECC608A-TNGLoRaWAN. The output of this operation can be used in the AES-GCM AEAD functionality. This mode does not involve secrets or anything stored on the chip. If this mode is selected, the remaining mode bits are ignored.

Table 1. AES Galois FIeld Multiply (GFM)

Opcode
(1 Byte)

Mode
(1 Byte)

KeyID
(2 Bytes)

Data
(32 Bytes)

 Description
0x51

0x03

 0x00 00
  • First 16 bytes - H-Field
  • Second 16 bytes input data
  
Table 2. AES GFM Output Response
Name Size (Bytes) Notes
Response 1 If the operation fails, the output is a one-byte error code.
16 If the operation is successful, the device will output 16 bytes result of the GFM calculation.
Parent topic: AES Command