cryptocell vs infineon optiga trustx platform

RE: cryptocell vs infineon optiga trustx platform

Vidar Berg — Wed, 22 May 2019 12:16:24 GMT

Hi Vedat,

We do not have a generic whitepaper on security, unfortunately.

It should be difficult and costly to hack and reverse engineer the IC even if any side-channel attacks can make it leak information. I'm not a security expert, so my best suggestion is to try to determine a reasonable security level based on the threat level and potential impact. E.g., how likely is it that someone may consider investing the time and money needed to achieve this? If keys are extracted from one device, will the other units become vulnerable? etc.

[quote userid="75799" url="~/f/nordic-q-a/47381/cryptocell-vs-infineon-optiga-trustx-platform/188185"]Is there any example of ACL and APPROTECT usage with full example of how to enable and disable?[/quote]

We don't have a full example of this. But readback protection is typically enabled by setting the APPROTECT.PALL field through the programmer (APPROTECT can be set at runtime by the FW if necessary).

With nrfjprog:

nrfjprog --rbp ALL

For ACL you either use the HW abstraction layer (\modules\nrfx\hal\nrf_acl.h) or access the ACL registers directly. You may also use our bootloader example as a reference, it uses ACL for flash protection.

RE: cryptocell vs infineon optiga trustx platform

ozanoner — Tue, 21 May 2019 10:00:13 GMT

Hi Vidar,

Thank you for the insight!

Is there anything else that I need to be aware of as physical attack types like explained here? Do you have any whitepaper that you can suggest me to read regarding to nrf52840 or any of your products in general which explains security issues?

So I can lock any flash region by using ACL at the moment of assigning IDs and keys, and then enable access port protection. I don't know if you have knowledge of 802.1AR (Secure Device Identity) standard, but this technique seems to solve this requirement. Is there any example of ACL and APPROTECT usage with full example of how to enable and disable?

Best wishes,
Vedat

RE: cryptocell vs infineon optiga trustx platform

Vidar Berg — Tue, 21 May 2019 07:20:55 GMT

Hi,

You're right in that Cryptocell and Optiga TrustX platform provide similar functionalities. I think the key difference is that TrustX offers tamper proof NVM storage. The nRF52840 is not designed to protect against physical attacks such as decapping of the IC.

The Cryptocell has secure key slots in a protected always-on domain (secure RAM) to which keys can be written and subsequently used by the Cryptocell core, but never read back. The key must be set in the Cryprtocell's always-on domain after every reset, so it must reside in flash to be persistent. To protect the keys in the 52840's flash, you can lock down the debug interface by enabling APPROTECT and use the Access control lists (ACL) to prevent read access from other parts of the code (can only be unlocked by reset).

Best regards,

Vidar