I recently implanted a NExT v2 and was doing some research into write protection. I came across an old post where Amal mentioned the xSIID (same NTAG I2C chip) is already “sorted out at the factory” before shipping. Does this apply to the NExT v2 as well? And if so, what exactly does that configuration include? Is there a default password set, and should I change it to something personal before using it in the wild? I really want to just stick my hand in every reader I find for the blinkies but I’m afraid of some NFC interactions in the wild messing with the lock bits or writing to it and making it unusable. The last thing I want to do is brick my brand new implant
page 2 shows lock0 byte is 0F which means the lock bits themselves (and the CC in page 3) are locked. this means you cannot modify the lock bits (they have locked themselves) which means you can’t accidentally lock your tag memory as read-only. yay.
page E2 shows lock2 as also locking all the dynamic lock bits that govern the rest of user memory that lock0 and lock1 don’t cover. so you can’t lock any part of the user memory as read-only. yay.
page E3 contains AUTH0 which sets the memory page at which password protection is required (from AUTH0 page down, so page E3, E4, etc). there are important configuration bytes for your tag that begin at page E3 and the AUTH0 byte is set to it’s own page E3 which means in order to change your own configuration bytes you’d have to first authenticate with the current password. this makes it harder to accidentally muck up a configuration byte that could result in unwanted consequences. what sort of consequences? this is where reading the spec doc for the NTAG chip in the NExT 2v becomes important. it’s linked on the product page.
I see, thank you! From what I understand then; I should still be able to write to the user memory without having to unlock correct? Ive been trying to write a simple text record to it as a little test with NFC tools but I keep receiving a “write error”.
iOS has a very hard time working with NFC transponders in general because it’s very narrowly focused on specific features. One of the things it doesn’t do too well with is a faulty ndef record. Basically the underpinnings are designed to modify an existing record but if the record gets corrupted because, gee, I don’t know, maybe this is a very delicate magnetic coupling technology and the user might have moved the phone while it was trying to write something and left an incomplete ndef record.. well then, iPhone basically throws up it’s hands.
I would suggest finding an Android phone and trying tagwriter first. There are some format options but I would skip that and just write a record. Once you have a working ndef record then iPhone can deal with it.
I don’t think so. I think just NFC tools on your phone was unable to fix the problem that was there already. The ndef record was malformed. That was the cause of the problem. Haven’t got that way, who knows.. but anything is possible because this is a very fragile communication method and malformed data can be very common.
