How To Undo Change Access Key 0F On NTAG 424

[echai]

I recently accidentally changed the file settings of my NTAG 424 using NXP TagXplorer. I've set the Change Access Key to 0F, which basically means no access. Does that mean that my tags are permanently locked now and I cannot update the file & SDM options, mirroring, etc? This is the error that I got

My settings:

The error I got:

How can I fix this? Thanks!

[authways]

Hello @KellyLi. I am also working with NTAG424, I have hundreds of cards already bought. How can I avail the NDA? I did not want to make a post about it, but if there is no response from you in the next few hours I might have to make one.

[KellyLi]

Hello @echai 

Thanks for contacting us and using the NXP products.

Based on your issues description, it's recommended that you choose the RFID Discover tool to debug your device, but which is available under an NDA. If you've already had an active NDA, please log in RFIDDiscover | NXP Semiconductors to download the following documents.

BR

kelly

[echai]

Hi @KellyLi, thank you for your reply.
I am open to signing an NDA to have access to this software. Where can I do that?

Also, is there no way to remove the 0F lock using NXP TagXplorer? Thank you.

[KellyLi]

Hello @echai 

1.  If Change Access Key, first you should make authentication using the key, and then key access can be changed.  you can try on TagXplorer. But for the better, it's recommended RFID Discover which feature is not restricted.

2. Please establish an NDA with NXP by going to  https://www.nxp.com/support/support:SUPPORTHOME and select "Request an NDA"

BR 

kelly

[echai]

I think there might be a slight misunderstanding.

My change key is set as 0F. This means that I cannot change any file settings anymore because the change permissions literally mean no permission. How can I undo that or change my change key as seen in the screenshot? Can RFID Discover do that?

[KellyLi]

Hello @echai 

I have made a test on RFID, but your action is risky, I don't have enough labels here. So, suggest that you can try to use Masterkey to make authentication and then modify changeAccessKey to 0x00 or the other values. Maybe it can be changed back.

BR

kelly

[KellyLi]

Hello @echai 

First you need to sign an NDA with NXP, after that, you can go to docstore.nxp.com to apply for RFID Discover (Sw186654 - RFID Discover V5.4 (5.4)) and User manual (UM253854) download. Finally you can install and use.

BR

kelly