Crypto Engine Use With Lorawan V1.1.X; Figure 11-1: Key Derivation Scheme For Lorawan 1.1.X - Semtech LR1121 User Manual

11.3 Crypto Engine Use With LoRaWAN V1.1.x

All the keys required to sign, authenticate, or encrypt Join traffic, as well as the session keys, can be derived from the
provided root keys (AppKey, NwkKey), following the derivation scheme described in
CryptoDeriveKey(...) function should be computed by the host controller, and supplied to the function as its
Input[1:16] argument, with appropriate padding bytes when applicable. For instance, when computing FNwkSIntKey, the
command should be used as follows:
FNwkSIntKey = CryptoDeriveKey(NwkKey, 0x01 | JoinNonce | NetID | DevNonce | pad
Where pad is the required number of 0x00 bytes to expand to a 16-byte number.
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Figure 11-1: Key Derivation Scheme For LoRaWAN 1.1.x

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Figure 11-1. The arguments of the
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