Password protected but not read only?

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1

NeXT —XNT side
Somehow haha I set a password I know what it is
However.

My tag still allows itself to be written to

Am I only protecting the tag from being LOCKED?

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This is my reading and writing with only NFC TOOLs

2

Yes that’s exactly it: your tag is protected against bricking (well, if you used the DT app to set the password anyway), not against writing.
You can use the password to write-protect parts or all of your chip too.

If you didn’t use the DT app to set the password, your chip isn’t protected against anything at all: you just set the password, is all.

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To expand upon what @anon3825968 said: you likely set a password for the HF side of your NExT, but the AUTH0 byte is still set to E2 which means only the configuration pages at the end of the NTAG216’s memory are protected. If you want to protect pages earlier than that (like the content of the tag itself) you will need to set AUTH0 to the first page that you want to password protect.

See the NTAG216 datasheet for more information, pages of interest are 12 and 18-19

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4

Thanks. I’ll download and read it on the throne

5

^^^ This!
I don’t own/have access to an NFC phone so my NeXT is unprotected till I can get myself a rinky-dink NFC phone. Almost bricked the damn thing while stupidly trying to experiment with Ntag data that wasn’t the same as my NeXT

6

Actually it is somewhat protected - the configuration pages at the end of the tags memory are read only without the password. It should be pretty hard to brick it unless you enter the password DNGR (in hex). See the NTAG chip security section of the product page for more info about what DT does to each implant before shipping

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For an incredibly detailed explanation plus exactly what pages / bytes are set to what see: