Proxmark3 community

Research, development and trades concerning the powerful Proxmark3 device.

Remember; sharing is caring. Bring something back to the community.


"Learn the tools of the trade the hard way." +Fravia

You are not logged in.

Announcement

Time changes and with it the technology
Proxmark3 @ discord

Users of this forum, please be aware that information stored on this site is not private.

#1 2017-02-07 17:22:31

trazodone
Contributor
Registered: 2015-11-25
Posts: 50

The meaning of 4 Hex leading wiegand 26 bit card number

Hello,

I have EM card with number 0005959403 090,61163

When I use card calculator for Facility code=090 and Card number=61163 I can get 0x00005aeeeb
BUT when I use PM3 to read from card I have 0x36005aeeeb
I found issue in some case of I write 0x00005aeeeb then the reader of door did not allow me to open. and when I use 0x36005aeeeb then I could open the door. I tried to googling around but there is very few info to describe of this hex number. I would like to know the meaning of leading 4 Hex character.

Thank you.

Offline

#2 2017-03-22 02:49:59

hkplus
Contributor
Registered: 2015-01-07
Posts: 127

Re: The meaning of 4 Hex leading wiegand 26 bit card number

The EM card can both be represented by a facility code and card ID OR it can also be represented by a straight 10 digit ID number on the card.  Often, EM cards will be both marked with the FC + ID followed by a , and a ten digit number that is the data equivalent to same bit value on the card.  Some controllers break the fields up into FC + ID and some use just the 10 digit number.  On systems that use the FC + ID, the leading digits are often ignored so you don't have to worry about this value much.  On systems that use the entire number, you will have to make sure that the leading data is correct.  Either way, changing the leading data may not affect the card from being read on the reader.  I know that certain manufacturers put data in this upper field area in order to prevent standard EM cards from working on specific hardware.

Offline

Board footer

Powered by FluxBB