Signing of ncs-serial-modem firmware

RE: Signing of ncs-serial-modem firmware

Samruddhi Jadhav — Mon, 12 Oct 2026 08:14:36 GMT

[quote user="ST-Kon"]For NTN modem, is it possible to do delta OTA from 2.0.4 to ntn-1.0.1?[/quote]

No. Only Full modem DFU with nRF91M1 for NTN update (delta would be far too big to fit to the reserved partition), or full modem FOTA with custom build (and external flash). For NTN updates, we recommend you to do the full modem DFU to NTN FW in their production rather than on the field.

Best Regards,

Samruddhi

RE: Signing of ncs-serial-modem firmware

Konstantin Klitenik — Fri, 09 Oct 2026 13:11:40 GMT

Is public key something we can request? I would love to be able to support both on our device.

Let me know if there is a separate point of contact for this.

For NTN modem, is it possible to do delta OTA from 2.0.4 to ntn-1.0.1?

RE: Signing of ncs-serial-modem firmware

Samruddhi Jadhav — Fri, 09 Oct 2026 09:03:42 GMT

Hi,

[quote user="ST-Kon"]Are there any plans to ship NTN modem fw with nrf91m1?[/quote]

From our production, nrF91M1 will ship with mfw_nrf91x1_2.0.4. You can update it to NTN FW as given here: Introduction — nRF91M1 AT Commands 1.0 documentation

[quote user="ST-Kon"]If we wanted our mcuboot to allow both nordic private signed and our own signed, is the public portion of the Nordic private key available in the repo so we could include both in our mcuboot?[/quote]

This is currently not available.

Best Regards,

Samruddhi

RE: Signing of ncs-serial-modem firmware

Konstantin Klitenik — Thu, 08 Oct 2026 13:48:52 GMT

If we wanted our mcuboot to allow both nordic private signed and our own signed, is the public portion of the Nordic private key available in the repo so we could include both in our mcuboot?

RE: Signing of ncs-serial-modem firmware

Konstantin Klitenik — Thu, 08 Oct 2026 13:40:15 GMT

Thank you.

Are there any plans to ship NTN modem fw with nrf91m1?

RE: Signing of ncs-serial-modem firmware

Samruddhi Jadhav — Thu, 08 Oct 2026 07:58:32 GMT

Hello,

Just an update on this from the team. We have just made this signing for the first time officially today after creating v2.0.0 release. The signing is done outside the GitHub actions that have generated the current release artifacts. We will share the resulting binaries in GitHub also as: serial_modem_v2.0.0_nrf91m1.zip in the next few weeks.

This will be the exact same Serial Modem feature content as: serial_modem_v2.0.0_nrf9151dk_nrf91m1.zip with the exception of the signing. The latter is signed with NCS developer key and the former is signed with Nordic's private key.

nRF91M1 is a product that will get serial_modem_v2.0.0_nrf91m1.hex binary and mfw_nrf91x1_2.0.4: nRF91M1 - nordicsemi.com

Please let us know if you have any further questions.

Best Regards,

Samruddhi

RE: Signing of ncs-serial-modem firmware

Samruddhi Jadhav — Wed, 07 Oct 2026 11:57:27 GMT

Hello,

I am looking into this and will have to discuss it internally with the team. I will get back to you soon with an update by this week once I receive any further information.

Best Regards,

Samruddhi