NTAG 424 DNA server-side challenge

[ondrejnedoma]

I want to use the NTAG 424 DNA to do the following, but I can't figure out what instructions I should send to the tag: 

• Using my app, fetch a random challenge string from my server. It's valid only for a few seconds.
• The app should send it to the string for it to encrypt the challenge with a secret key (this key should be only known to the tag and the server) and send back the encrypted string to the phone
• The app submits this encrypted version to the server, which can verify that the tag has actually been scanned, because it knows the key

Is this even possible using the NTAG 424 DNA? Or would I need a different chip, possibly a Javacard based one?

[Fabian_R]

This is Fabian, I've been assigned to support your case.

I appreciate your interest in our products.

Hello sir, I believe that the solution for this might be to explore the usage of NTAG's 424 SUN. Please take a look at this feature in our Datasheet and, also in AN12196 section 9 System implementation concepts.

This will help you understand how the ecosystem works and, what could you use to implement a secure environment.

In the backend, if you need to, please take a look at our cloud service: NFC services for a full implementation.

https://www.nxp.com/products/wireless-connectivity/nfc-hf/ntag-for-tags-and-labels/ntag-secure-servi...

[synadimauro]

Dear Fabian,

I'm looking at NXP solution for NFC server full implementation, in particular, related to the NTAG 424 DNA.

I check the link you post:

https://www.nxp.com/products/wireless-connectivity/nfc-hf/ntag-for-tags-and-labels/ntag-secure-servi...

but I was not able to find out the detail of such product 

NTAG Secure Cloud Platform

Can you help me on getting started with that?

Thanks

[Fabian_R]

Hello sir,

Since this is a service it is necessary to contact the respective team the following mail:  nfcservices.support@nxp.com

I highly recommend to please get in touch with them through our Distributors, they will have more information about this service. I'm very sorry sir but, there are some secure services to which I don't have access to information.