Thinking about getting one

It’s just easier for us to see what we are dealing with so we can better help you


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When i thought about it, i do not need to use it for public transport it would be just cool gimick for me. So it would be probably easier and better to focus on my main use case. I wanted to make my life a bit more convinient if im already researching this stuff but, the main problem for me is that i do not want to have multiple implants. I understand that there are limitations but it is just no go for me. I like to have it simple. My main use case is storing securely very small amount of text. Like few words maybe 5 sentences and in best case for a long time without corruption. Other features are bonus for me. What would you recommend in this case ?

Sorry for always changing things i would want.

xDF2 has 8kb but its a bit work to set it up.
If I was you I’d go NExT because that likely also covers your access card and you have almost 1Kb of room for text.

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I concur

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We all were at that point, but a keyless/cardless life is worth some stabs.


Ok i checked NExT and it seems like exactly what i would want. I roughly tried to write the amount of text i need and it seems that even though there is not that much memory, it is more than enough for me.

13.56MHz NTAG216 NFC Chip

  • 13.56MHz NXP NTAG216 ISO14443A & NFC Type 2 chip
  • Full datasheet for the NXP NTAG216 RFID/NFC chip
  • 7 byte UID and 886 bytes of user read/write memory
  • 10 year data retention. Rated for 100k writes per memory block.

What is the all stuff i need to read/write to both of these chips ?

xDF2 has 8kb but its a bit work to set it up.
Why it is “a bit of work” to setup ?

It seems that xDF2 is even better because it has higher data retention:

  • 13.56MHz ISO14443A & NFC Type 4 DESFire EV2 RFID chipset
  • Full datasheet for the NXP DESFire EV2 RFID/NFC chip
  • 7 byte UID and 8K bytes of user read/write memory
  • 25 year data retention. Rated for 500k writes per memory block.

Speak for yourself, I came in like a wrecking ball :upside_down_face:

Someone’s gotta beat @JennyMcLane and @Vicarious for the high score

A couple points to consider, as it looks like your looking at the NExT (a solid all around multi function chip)

The NExT isnt “secure” per se

Someone could scan you chip and get it’s full payload, highly unlikely for a multitude of reasons…

but I don’t want you thinking the NExT is going to protect whatever you put on it, most of the more basic chips
xEM (t5577)
xNT ( ntag216)
NExT ( t5577 and ntag216)
Are literally designed to shout their info when ever a reader reads them

If you want the data to be secure, you’ll need to encrypt it on a computer or phone first, and then copy the encrypted text to the chip

Which I’m guessing might defeat your purpose, I think the some of the more secure stuff like the xDF or other desfire variants don’t reveal payload unless prompted the right way

@Pilgrimsmaster, I don’t know enough about desfire to advise, any input or anyone a go to?

About the data retention, it SUPER sounds like we’re just talking about crypto passwords and what not

As much as I like the idea of storing something like that in a chip as a failsafe, don’t forget the that the chips aren’t indestructible or infallible… shit happens sometimes… make sure all your eggs aren’t in one basket

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So xDF2 would be safe if stored with weak or no encryption ? There was said that it is “a bit of work” to setup. What does it mean exactly ? I would like to try it first with some card type of xDF2 if i would decide for that one.

I think we need to clarify some stuff before we get wires crossed

Define what you mean by “safe” and what are you storing?

The more info you give us the better we can advise
You don’t have to reveal exact text or anything like that

Ok, still you figured it out lol. I was thinking of storing crypto keys on it as fail safe. I know that i need to have it stored in multiple places to not lose it. So do not worry about that part :smiley:. Safe i mean that even if somebody knows about it and reads the tag, the tag is not going to spit it out without password for example.

That’s fine, crypto is a thing (I personally don’t mess with it cause I’m lazy lol)

So no I definitely wouldn’t put your crypto password in plain text on a NExT or xNT, anyone that can manage to get a scan can get everything in plain text

The xDF2, has mutual authorization which I think means it won’t reveal data unless specifically requested, it was designed from the beginning to be more secure than the previously mentioned stuff by verifying who’s asking before blurting everything out

Still need to talk to someone far more experienced with desfire than me,I only know surface level stuff

So it still needs to be encrypted on my part othervise it would still spit it out ? Problem is that somebody needs to show up who knows about this stuff more because i do not know anybody. That is why i came here.

btw what is the record count ? lol

You can encrypt bitcoin private keys as BIP38, memorize the password and write the encrypted key as an NDEF record to a NExT implant. Sure, anyone will be able to read it but they will need the password to use it. Just make sure to use a strong password or passphrase.

And you might be able to clone your work badge to the LF side of a NExT.

It’s also possible to use the xDF2 in NDEF mode without any security. And at least with the Desfire EV1 chips, is not that hard. I’d mention my experience with the Desfire EV2 but I’ve never used it and I’m still waiting for my xDF2 to make it out of customs limbo…


I figured as such… so you do have a few options as mentioned above.
here are a couple more I would also suggest to add to their options

Use TagWriter or NFC Tools and write out your keys as a plain text NDEF, depending on how many wallets you have your total size should be less than ~888 bytes

You could buy a dedicated xNT for example and write that record to that implant, and only use it for that one purpose.
Pretty cheap and safe way to store the info.
I would also mention, you would probably want to Read it at least once every 10 years, but more frequently would be better, just to refresh the data retention. (another physical backup would be sensible)
Don’t tell anybody you have it, put it somewhere less convenient than a hand (Thigh, back, shoulder, bicep…)

put the location and information on how to access it and what to do with it in your will. (makesure your will is enacted before you are cooked :fire: or buried.)
The chances of somebody scanning your body whilst you are alive and stealing your keys, in my opinion are very Low.
Unless you are super loaded :moneybag: but then still do the same, but also

Another option is use something like OpenKeyChain : Easy PGP to encrypt your data, and write this to your implant and again to decrypt when you read it

Another is get a NExT now, because they are awesome and wait for the SOON™ to be released Apex that which have a number of options for you including encryption and key storage

Ok i will have a bit deeper look in to it. Thank you.

Problem is that im using mnemonic seed so in that case i do not know what should i use to encrypt it. Do you know about something i could you for this ?