Infineon OPTIGA Trust X on nRF52840?

[manumonti]

Hi all,

I'm interested in adding Infineon OPTIGA Trust X to nRF52840, but I can't found enough information.

Is Infineon OPTIGA Trust X hardware-compatible with nRF52840-PDK. I mean pin compatible.

Can I see any picture about how this two devices looks together?

And, finally, I have seen in documentation and SDK v.15.0.0 some support for nRF52832 (pca 10040), but not for nRF52840. Does it exist some support for nRF52840? If not, could be easy to adapt the code for nRF52832?

Thank you in advance,

Manuel Montenegro

[Jørgen Holmefjord]

Hi,

Communication with the OPTIGA Trust X device is using I2C/TWI bus. The TWI peripheral on nRF52840 is the same as the one on nRF52832, so I do not see any potential issues with running it with the nRF52840. Most likely there is no project for nRF52840 as it is not sufficiently tested yet.

I have not tested running this on nRF52840 myself, but I will look into trying it out when I get my hands on the HW module.

I would recommend you to try it out and report back if you are facing any issues. If you do face issues, we will help you resolve it.

Best regards,
Jørgen

[manumonti]

Thank you for your answer, Jorgen.

Manuel Montenegro

[Jørgen Holmefjord]

I did a test with the OPTIGA Trust X project for PCA10040 (nRF52-DK) on the PCA10056 (nRF52840-PDK). I had to do some small modifications to the pinout in the code in order for it to work without midifications of the PDK:

• Change Reset GPIO from 18 to 29 in file nRF5_SDK_15.0.0_a53641a\external\infineon\pal\nrf5x\pal_ifx_i2c_config.c:64
• Change Power GPIOs from 19 and 20 to 30 and 31 in file nRF5_SDK_15.0.0_a53641a\external\infineon\pal\nrf5x\pal_gpio.c:46-51

By default, GPIO P0.18 is used for RESET and GPIOs P0.19-P0.20 is used for external flash chip on the PDK, and is not connected to the pin header. If you want to use these GPIOs, you need to modify the PDK as described in the documentation.

[Jørgen Holmefjord]

Out of curiosity, could you share what you are planning to use the Infineon OPTIGA Trust X for together with the nRF52840?

[manumonti]

Hi, Jorgen. Let me explain...

I’m working in a research project about Intelligent Transport Systems. Currently we are studying how to authenticate Bluetooth5 advertisements in long range mode. That’s the reason why we are using nRF52840 (in fact, we are waiting for support of real extended advertisements-more than 31 bytes data-).

We had a look to nRF Cryptographic library and OPTIGA Trust X. Firstly, we considered that Trust X is more secure because the keys can be saved on chip without possibility of exporting it.

But, after that, we saw a post about CryptoCell system that looks interesting. Maybe we can use this joined with Access Control Lists (ACL), in order to protect flash memory’s regions where keys is stored. We saw this possibility on this post.

What would you recomend us?

Thank you!

Manuel Montenegro.

[Jørgen Holmefjord]

Thank you for the feedback. There are some root-of-trust capabilities in the CryptoCell, but unfortunately support for this is not yet implemented in our libraries. You should be able to protect flash regions by using the ACL peripheral. If you need an Optiga Trust X device will depend on your required level of security and certification.