2001 Oct 04 10
Philips Semiconductors Product specification
HITAG core module hardware HTCM400
7.5 Security considerations
Developing the HTCM400 special consideration was given
to aspects of security. The following items represent the
fundamental framework of the security concept:
• Cryptography
• Mutual authentication
• Password verification and
• Cyclic Redundancy Check (CRC).
7.6 Data reliability
All the commands and datatransferred from the HTRM440
to the transponder are secured by Cyclic Redundancy
Check (CRC).
7.6.1 CRC OF A DATA STREAM BETWEEN READER
MODULE AND TRANSPONDER
This check is carried out in the transponder.
Every data stream sent (commands, addresses and user
data) from the HTRM440 to the transponder is first
checked for data errors by a transponder-integrated 8-bit
CRC generator and then executed. Normally the
transponder responds to each data stream from the
HITAG proximity reader module with an acknowledge
signal or with a data signal or with a data block. The CRC
is formed over commands and addresses or the plain data
respectively and in the case of encrypted mode it is also
encrypted. The generator polynomial of the transponder
CRC generator reads:
u
8
+u
4
+u
3
+u
2
+ 1.............. = 0x1D
and the CRC preassignment is: 0xFF.
Detailed instructions how to use and calculate Cyclic
Redundancy Check (CRC) are available in an additional
document.
7.6.2 CHECKING USER DATA
This check is carried out in the HITAG proximity reader
module.
Security of the data read from the transponder by the
HITAG proximity reader module remains with the user for
reasons of flexibility. Therefore, you can choose flexible
check sums and store them in the EEPROM together with
the data. You can protect sensitive data better than less
sensitive data, thus permitting optimized operation times.
7.6.3 DATA PRIVACY
The use of cryptography (Stream Cypher), mutual
authentication and password verification prevents
monitoring and copying the data channel. Therefore, the
area of the transponder that only can be accessed
enciphered is called ‘secret area’.
To make use of cryptography you need secret data: keys
and logdata.
Keys are used to initialize the crypto block and logdata are
used for mutual authentication.
The transponders and the HITAG proximity reader module
are provided with identical transport keys and transport
logdata so that you can start operating them right away
(see Table 1).
Table 1 Transport values predefined by Philips.
In order to offer our OEM clients high flexibility, the
configuration of the transponder, memory, password, keys
and logdata can be changed. We strictly recommend to
rigorously restrict these possibilities for the end customers
(by setting the configuration page to read only, setting
password, keys and logdata to neither read nor write).
See also “
HTCM400, HTRM440 Family, HTRM800 Family
Interface Protocol Reader - Host
”.
7.7 Operating security
The following mechanisms ensure the operation security
of the HITAG system:
• Anticollision mode
• Monitoring the supply voltage
• Antenna rupture or short-circuit.
SYSTEM PARAMETER VALUE
HITAG 1 keyinit password 0x00000000
keys 0x00000000
logdata 0x00000000
HITAG 2 keyinit password 0x00000000
key 0x4D494B524F4E
password TAG 0xAA4854
password RWD 0x4D494B52
