5.2.3.1 Sign - External Message

The Sign command can be used to sign the digest of an external message by an ECC private key. The message must be compiled and the digest of the message generated by the host system. The message can be loaded into either the TempKey or Message Digest Buffer via the Nonce command run in fixed mode and is always 32 bytes in length. The message always resides in the lower 32 bytes of these locations.

For the ATECC608A-TNGLoRaWAN device, Slot 1 is enabled to sign external messages.

Table 5-48. Input Parameters - Sign External

Opcode
(1 Byte)

Mode
(1 Byte)

KeyId
(2 Bytes)

Description
0x410x80 or 0xC00x00 0[Slot]External message digest stored in TempKey
0xA0 or 0xD00x00 0[Slot]External message digest stored in Message Digest Buffer
Table 5-49. Output Response - Sign External
NameSizeDescription
Response1 byteError code if the command fails
64 bytesThe signature composed of R and S values