Yubico Forum

I have a regular-sized NEO that I keep on my keyring. I have about six OATH secrets stored in it, and trying to read it with my Samsung Galaxy S4 is pretty difficult unless I remove it from the ring. A few questions:

1. Has anyone else had similar issues with the S4? Is it known to have weak NFC?
2. Is this a common problem with the NEO?
3. What are people doing to get around it? Should I hang the NEO off a smaller ring instead of having it attached directly to the large ring?
4. Where is the NFC antenna in the NEO?
5. Is the NFC antenna on the battery in the S4? Is it worth trying to replace the battery to see if it fixes the problem? (It's a work phone and IT will replace the battery on request, so the only cost is actually walking over there.)

GPG and OATH over USB work fine, by the way (Arch Linux). I had to write a script that kills scdaemon, then waits a few seconds before starting yubioath-desktop-disable-systray. Next time I use it for GPG, scdaemon starts up automatically and I get prompted again for my PIN, which is fine.

Do you use any sort of case for the phone? If so, try the phone out of the case, as it is possible there's something in the back of the case that interferes with the coupling of the NFC antennas in the phone and Neo.

I can't remember whether the S4 has an NFC antenna in the battery or not. If there are four battery contacts, it is likely the NFC antenna is in the battery. Third party batteries don't always have an NFC antenna. Samsung batteries for phones with NFC often say "Near Field Communication" somewhere on the battery - on the Note 3 batteries I have to hand it's under the Samsung logo.

If you have a third party wireless charging insert, that will almost certainly interfere with NFC unless the insert also contains an NFC antenna. Samsung's official wireless charging backs and wireless charging cases have NFC antennas as well as the Qi pickup coil.


So far as hanging the Neo, you can always use a lariat (one of those pieces of cord with a ferrule and small ring on it) to increase the distance between the keyring and the Neo. It might be that the presence of all the metal on the keyring is interfering with NFC.

I tend to hang devices like Yubikeys from a ring using a lariat and lobster clasp so that I can easily unsnap the Yubikey from the ring to use it and return it to the ring when done. Lariats and lobster clasps can be acquired cheaply from eBay, Amazon and the like.

I have no case and no wireless charging. The battery does say "Near field communication" on it. I'll try the lariat and see if that helps. I imagine it will since taking the NEO off the keyring seems to help. I just wanted to make sure that this wasn't an unusual problem that might indicate a defective NEO or phone/battery.

Thanks for the quick reply and the suggestions!

(Leaving this as "question" for now in case anyone has specific S4 experience and wants to chime in. Happy to change it if that's a violation of protocol.)