Mifare Ultralight C authentication Problem

Hello,

I'm trying to authenticate ultralight c with NXP's MFRC500. I've try to following the authenticate method in the libfreefare. Everytime I send the AFh command together 16 bytes ek(RndA + RndB) with transceive method, I got only one zero byte answer from the ultralight c. I can't find any information or example from the internet and I've never receive any answer from NXP no matter how many time I send a support request. Please help.

Thanks!

Hi... Have the same problem... Working with a MIFARE 523 Reader and want to perform an 3DES authentication.

My question is: how do i get the token ek(RndA + RndB') which i need to send with the AF command?

I hope u can help me

with kind regards

Mexx