RT1020: ctr_nonce calculation algorithm, when is applied?

mastupristi — Thu, 20 Nov 2025 18:13:25 GMT

Hello,

I usually compute the ctr_nonce for BEE taking the nonce[127-32], and in the LSW I put address r-shifted by 4.

This is confirmed by documents [redacted] and also by code provided by SDK examples:

I usually use SW key or SW_GP2 key, and this simple algorithm make BEE works well.

However, I found another algorithm, significantly more complex:

[Redacted]

I wonder when this algorithm is used by BEE, and I would like more details on how H7 and H8 are used, because it is not clear from the drawing.

best regards

Max

Note: Some information or images have been removed as they referred to moderated information.

Re: RT1020: ctr_nonce calculation algorithm, when is applied?

Sam_Gao — Mon, 03 Nov 2025 09:25:29 GMT

’However, I found another algorithm, significantly more complex....‘

@mastupristi What is your purpose? Please tell me the source of this screenshot, NXP's publicly available information has listed what can be disclosed.

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RT1020: ctr_nonce calculation algorithm, when is applied?

Re: RT1020: ctr_nonce calculation algorithm, when is applied?