Samsung Galaxy SIII returning different UIDs...

Asked by Juan Trujillo on 2015-12-16

Every time I put my Samsung Galaxy SIII close to my NFC board, I see a different UID. Shouldn't it be the same? If this is expected, how can I force my phone to provide the same UID always?

I'm asking this since when I use a regular/standard (Type2Tag) I always see the same UID. I need the UIDs to be the same always on my phone since I'm using this field as a key to register/unregister a user on my app.

Here are examples of the information I see on my R-Pi when I'm pairing my phone:

Type4Tag ATQ=4403 SAK=20 UID=08c0d6d1285c0e ATS=0578338802
Type4Tag ATQ=4403 SAK=20 UID=080c03fce3816a ATS=0578338802
Type4Tag ATQ=4403 SAK=20 UID=081d776f748f18 ATS=0578338802

And this is the output for a Type2Tag (always the same):

Type2Tag ATQ=4400 SAK=00 UID=0477037a8c3384

Thanks,

-Juan

Question information

Language:
English Edit question
Status:
Answered
For:
nfcpy Edit question
Assignee:
No assignee Edit question
Last query:
2015-12-16
Last reply:
2015-12-16

That's pretty standard, phones do not usually have a fixed UID for card emulation (the first byte 0x08 tells that it's random).

Can you help with this problem?

Provide an answer of your own, or ask Juan Trujillo for more information if necessary.

To post a message you must log in.