Can bootloader support RSA 3072 for nrf5340?

[Jaewook]

Dear,

We are llooking for an example to use RSA 3072 for nrf5340 bootloader.

How can bootloader (samples/bootloader example) support RSA 3072 for nrf5340?

Regards,

Jae

[Jørgen Holmefjord]

Hi,

The ARM Cryptocell CC312 in nRF5340 supports RSA up to key lengths of 3072, but the cc3xx backend in nrf_security is limited to a key size of 2048 (likely since CC310 in nRF9160/nRF52840 only supports key size of 2048).

If you want to use RAS 3072 in nRF5340, you can use the Mbed backend, which has no limitation in key size. This backend does not use HW acceleration through the Cryptocell peripheral.

Best regards,
Jørgen 

[Jaewook]

Thank you for your quick response!

Do you have any plan to support this feature in your Nordic sample example?

Regards,

Jae

[Jørgen Holmefjord]

Hi,

I'm waiting for feedback from our developers, if support for RSA 3072 is on the roadmap. Will get back to you as soon as I receive their response.

Best regards,
Jørgen

[Jørgen Holmefjord]

Hi,

I received feedback from our developers that RSA 3072 will be supported in the next release of nrf_cc3xx library.

Best regards,
Jørgen