Proxmark3 community

marcus2608

Contributor

Registered: 2009-03-26

Posts: 30

Controlling Tag Nonce

Hi,

I am looking at using the PM3 to get the tag to generate the same nonce every time in a card-only attack. After analysing the file iso14443a.c in the 20090409_prox package, I have absolutely no idea of how this can be done. Can any kind soul here who has managed to do this provide some hints? Thank you so much.

rule

Member

Registered: 2008-05-21

Posts: 417

Re: Controlling Tag Nonce

hint1: Drop down the field of a while and add a 100ms delay
hint2: Put a book between your antenna and the tag (seems to clean up the field-power better)
hint3: Restart the full anti-collision after getting a nonce
hint4: Try to keep your code clean and let it take the same branches to avoid timing differences

marcus2608

Contributor

Registered: 2009-03-26

Posts: 30

Re: Controlling Tag Nonce

Thanks roel, I will give it a try!