HID Identity FlexSmart MIFARE 6055BBL0010 Manuale Utente

Application Note 25 – Using the Model 6055B HID Mifare Reader  

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Once customers have purchased HID Factory Encoded MIFARE cards, they (or 
other application providers) can program additional data into other sectors on the 
card.  See the section on Transaction Mode for more details. 
 
Keys – A Brief Explanation 
 
A Key is basically a password.  The Mifare card uses 48-bit keys (typically 
expressed as 12 Hex characters).  There is one pair of keys, called the A key 
and B key, used to protect each of the 16 card data sectors.  Each key in a pair 
can be used to protect a certain function.  For example, the A key could be 
required to read data in a sector, while the B key could be required to write data 
to a sector; or the A key could be required to deduct stored value from a sector, 
while the B key could be required to add stored value.  To access data in a 
protected card sector, the reader must have a matching key.   
 
Keys are used to protect data from being read or changed without authorization.  
Because each sector has its own separate key pair, a Mifare card can be used to 
store information encoded on the cards by separate vendors for separate 
applications, and each vendor would be prevented from modifying the other 
vendor’s data accidentally or otherwise, simply by keeping the keys secret.  For 
this to work, the keys to the card’s Mifare Applications Directory need to be 
known to all parties.  Separate sets of readers would be used to control each 
application – each reader would have only the appropriate keys for its own 
application. 
 
Non-Factory Encoded Cards 
 
Many customers already own MIFARE cards that are encoded with transit, 
vending, campus or other applications, and they wish to add access control 
functionality to those cards.  This can be accomplished by connecting model 
6055B HID MIFARE Readers to standard access control panels.  
 
The easiest approach is to configure the HID MIFARE reader to output the 
MIFARE card’s 32-bit Card Serial Number (CSN) as Wiegand data.  The HID 
MIFARE Reader can be pre-configured to do this at the factory, or it can field-
configured with a configuration card.  Unfortunately, most access control panels 
require data formats with a fixed facility code and sequential numbering, and 
therefore cannot accept the 32-bit data.  A common workaround is to cut off (or 
truncate) some of the data from the 32-bit CSN and adding a fixed facility code to 
synthesize 26-bit Wiegand format data. However, this still may result in 
duplication of numbers, and will provide random rather than sequential card 
numbering.  This type of modification of CSN output can be configured on the 
6055B.