Specifications

Smart Cards Lab COMPGA12 University College London
See mifare.pdf that is distributed with rfidiot library. Depending on
installation directory it could be here: file:///C:/Program%20Files/
rfidiot/mifare.pdf).
Each sector with 4 blocks can be accessed using the same key. We can
choose to use key A or key B. Here below we will be only using keys A. These
two keys assigned to each sector of 4 blocks are stored in the last block of
each sector (sector trailer) but typically (depending on access conditions)
cannot be read, can only be written.
12.4 More Details on MiFare Classic
A detailed specification of the MiFare Classic card including low-level com-
mands cna be found here:
\Smart Cards Lab docs and free software\
documents\manufacturer data sheets\
It is also included with some CDs distributed with ACR 122 reader.
\Smart Cards Lab docs and free software\additional software packages\
Smart Card Focus ACR122 starter Kit with Sample C++ Code CD 2011\
User Manuals and Reference Materials\
A ready Python script for reading cards and copying them, provided
that they use default keys, is discussed in Section 13.11. A ready software
for Windows which allows to explore any card for which we know some cryp-
tographic keys and to study and understand access conditions is discussed
in Section 13.12.
12.5 Which Block to Use
One cannot write on the block 0 that is read-only, and which is enforced by
the manufacturer in hardware and cannot be changed.
Please do not write on sector trailer blocks that are: 3, 7, 11, 15, 19, 23,
27, 31, 35, 39, 43, 47, 51, 55, 59, 63 because they contain secret keys that
will be overwritten
In UCL cards one can freely write on blocks 4-59 that are NOT used.
From now on we will be working on block number (some recommended
values are suggested):
c
Nicolas T. Courtois 2009-10