Proxmark3 community

YoungJules

Contributor

Registered: 2012-01-29

Posts: 60

Identifying tags?

I have a bunch of tags here which I'd like to identify.

I have an LF and an HF antenna and a proxmark3

I have already discovered a few are Mifare classic, I've got a couple of HID cards but the rest are still unknown to me.

What is the procedure for dealing with unknown tags?  Can you tell if it's an LF or HF card just by watching the voltage change on the hw tune command?

Most of these tags will be 'blank' as they're new so all I'm looking for is to read the IDs for now.

Thanks and regards,
YoungJules

P.S.  Sorry if this is all in the FAQ or some other tutorial/guide but I haven't found it yet...

YoungJules

Contributor

Registered: 2012-01-29

Posts: 60

Re: Identifying tags?

Gosh this is a quiet forum, I often get the feeling I'm only talking to myself and 0xFFFF

Anyway, I found what appears to be a reasonably up-to-date list of commands for the proxmark3 here with thanks to comas

So today I'll try experimenting with these commands against the unknown tags I have.

I still welcome any and all suggestions for a kind of diagnostic process of elimination to figure out what a tag is.  So perhaps it starts with "if there's a voltage drop on the HF antenna, then it's an HF tag; if hf 14b read is successful then it's an ISO14443"... etc.

I'm particularly interested right now in some keyfob tags I have, they're grey (wow! that helps a lot, right?), each one appears to have a serial number on and I think they're LF tags...ideas?

Thanks and regards,
YoungJules

0xFFFF

Administrator

From: Vic - Australia

Registered: 2011-05-31

Posts: 632

Re: Identifying tags?

Hi YoungJules,

Could you post some photos of the tags perhaps?

BTW you're right about the quiet thing. 0xFFFF does not really exist. It's all in your head.

Regards,

The voices in your head

YoungJules

Contributor

Registered: 2012-01-29

Posts: 60

Re: Identifying tags?

Well the little grey keyfob tags are 125KHz EM Marin (I hope I got that right)

Is there a way to read the serial off them using the proxmark?  I only see the command "lf em4x em410xwatch" but that doesn't appear to give me the tag's serial number in a nicely readable format...

Thanks again
YoungJules

carl55

Contributor

From: Arizona USA

Registered: 2010-07-04

Posts: 175

Re: Identifying tags?

The EM410x tag embeds both horizontal and vertical parity bits so you must extract the data bits from the serial stream before the code will agree with the number printed on the tag. Here is a link to a chart on my website that shows how the card code relates to the entire bit stream. The chart was originally generated to show how to program a T55x7 card with the EM410x format but it can also be used to convert back from the raw bit code to a card number.
http://www.proxclone.com/pdfs/T55x7_EM410x_format.pdf

YoungJules

Contributor

Registered: 2012-01-29

Posts: 60

Re: Identifying tags?

Thanks for this Carl.  I'm comfortable enough playing with bits and bytes so I'll see if I can make some sense of this with the tags I have.

I'll have to put my glasses on to read the serial numbers manually

Raymond

Contributor

Registered: 2011-09-14

Posts: 30

Re: Identifying tags?

Hi YoungJules,

Those grey or blue keyfob tags that you buy from internet are most likely 125KHz EM Marine proximity tags.
Most of them have serial number programmed in them, for tracking purposes (Number of users).

Regards