Okay so I got my Proxmark3 in the mail today (ended up ordering one before moving, since France is closer). Conveniently, it came with a T5577 test card.
It successfully identified my company-issued tag as a 224-bit Indala tag. So I tried to clone it, but I did it in steps, to try and figure out the pitfalls when the time comes to do it on a chip implanted in my hand:
1/ I took a dozen readings and compared the UIDs, to make sure I got a solid read from the original tag. No problem there.
2/ I issued the clone command, but without the test card on the Proxmark. The Proxmark proceeded and told me it was all done. Uh oh… That means it blasts the programming commands without any checks whatsoever, meaning trouble if the coupling isn’t good enough. Not good…
3/ I placed the test card on the Proxmark, as well positioned as possible and redid the clone command. Then I re-read it several times and compared the UID against the original UID: half of it was corrupted, despite the test card having a full-size coil and being located perfectly over the antenna. Uh oh… The trouble I expected happened rightaway with an easy-to-read card. This really doesn’t bode well for operation with an implant.
4/ I redid the clone command once more, and this time the UID matched.
So, when I return to my new workplace, I’ll see if the (now properly cloned) test card opens the door. If it does, then I’ll order a xEM and a DT coupling coil. I think that’ll be a must. In the meantime, I’ll try to figure out if I can get the Proxmark to report the quality of the coupling in real time, so I can locate the implant as best I can before the final cloning operation. I may also encase the DT coil in a plaster cast of my hand so it stays put at the ideal location even if I move around. I can see this has the potential to end up in a bricked chip very easily…