Multiple Uses on One Chip? <- Newbie

Hi All,

First things first, I am new to this and I am by no means familiar with the technology after my few days of research. So please be kind and explain in lay terms if necessary :slight_smile:

I apologise if this question has been asked previously (and I am sure it has) but I could not find concrete answers in the FAQ or through forums. (Maybe I used wrong keywords or terminology)

It seems like the Apex will be a sure purchase, but in the meantime I would like my first implant, however I am missing a little information.

I am wondering which (if any) form of RFID (or NFC) chip(s) can perform multiple tasks with the one chip, without being rewritten. I have found answers to this that either contradict or perhaps the wording throws me off.

Basically I would like to install one chip in one hand, and be able to write to it for multiple functions. Perhaps opening a Smart Lock at the office, and also allowing me to Unlock my Phone, then unlock my PC and other similar functions all at once using the one written chip.

Is it possible to have multiple actions across multiple devices on only one chip, without rewriting it for a specific singular purpose each time, or is this why many members seem to have multiple chips?

If it is possible to have multiple functions on the one chip that can perform multiple tasks, are there any specific chips that I should look into getting for this purpose.

Further, to my understanding RFID has low and high frequency ranges, and NFC is a subset of this with a specific frequency. I understand this is on a case by case basis with the devices you are trying to use. But what would be the more “common” route to go for things like smart locks, readers to unlock PC, Phone related commands (I assume this would be NFC), Travel cards etc. I am looking for the more widely used of the options.

Thanks for reading a question you’ve probably heard asked before, and helping with my first implant experience


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The way most things use RFID is to use the UID (Basically the serial number) to verify that you are you. You set up whatever the thing is (PC/Door/etc) to accept that serial as a “key” You don’t program the chip, you program the thing you use the chip on.

These two questions are worded a little oddly, could you provide examples for what you mean by Multiple functions that can preform multiple tasks

NFC is Usually HF RFID and “RFID” is usually LF RFID. Most things you’d probably use it for these days are going to be HF. But work badges and a lot of existing badged doors still use LF, so that’s going to be something you’d have to do your own research on for your specific cases. Or get an NExT and just be done with it. (You’d have to worry about Dual-band readers, but that’s a whole other thing)


Thanks for the information!

I will try and word it a little better, which I think is the issue I’ve found in other posts also.

In the simplest terms I would like to have 1 implant interact with multiple things. I am happy to have 1 in each hand, but do not want to add more than that (not yet at least).

So with this in mind I would like to be able to come to work and unlock the door with my hand, then go home and unlock that door with the same hand. Maybe go for a drive and unlock the car with that
same hand (these are just examples).

What you’ve said has made me look at this slightly differently. And possibly answered my question if I understood you correctly.

Am I right in understanding that the implant itself has an ID, and that ID is static. The device you are interacting with is simply accepting the implant ID?

For instance a Samsung smart lock, you set up the lock and select user 2 to create a new tag, then place implant on the reader, which will store the ID of the implant to the lock and next time it sees the implant ID, the door will unlock?

I use this example because I set up an NFC ring from ebay with a Samsung lock today.

I was under the impression the device you interact with may have needed more than just the ID of the serial, however if my above explanation is correct, I have been looking at this the wrong way around.

If that is not correct please let me know.

Thanks again for taking time to answer

For the HF tags, Yes. The LF tags have ONLY an ID stored on them, and those can be rewritten if you choose to.

This is correct. HF tags have the ability to do extra things (Store business cards, open websites, etc) but for unlocking things and triggering switches, it’s nearly always going to be the ID that triggers that (I say nearly to cover my ass, I haven’t seen anything on here where a data record unlocks something, but It probably exists)

Yes, However. You’d need to do research to see if the lock’s firmware will allow you to use the implant you get. There’s been a lot of people on here lately getting upset at samsung for basically blocking their chips from being used due to formatting standards or some such. Case in point

Again, I don’t want to use an absolute, because someone, somewhere, has probably rendered that statement false. but in the majority of cases, yes. The device is coded to accept your ID, not the other way around.

You do have to take into account formatting of the implant and device (Which is why a lot of us have multiple implants) but as long as all that lines up, you’re good to go.


Thanks again, you have enlightened me with this information. I had it the wrong way around in my head.

Lastly, you recommended the NExT. Any other recommendations or would this be the best all round chip to get to cover the most ground (in your opinion of course).

Cheers mate!

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So that again comes down to use case. But for me, and the average person, it’s going to be the best first chip. It’s got Both HF and LF inside one capsule. Should allow you to get into most things you’ll encounter, and still leaves your other hand free, if you’re nervous about going outside the “Approved” install site.


The Yale Doorman door lock uses Mifare Classic chips (NFC / HF) and writes to the chip at each unlocking, in a futile effort to secure the chip. So yes, it definitely exists. Check out this thread if you want details.

As for multi-use, well I now use my Mifare Classic implant to open my Yale Doorman lock (with its reading/writing funky sectors business), but my implant’s UID is also used to unlock my home computer under Linux, and my work computer under Windows. And I’ll soon try to find out if I can write a valid NDEF message beyond the Doorman’s working sectors to encode my site’s URL and have it read by a cellphone, without making the chip invalid for the Doorman.

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