ACR3901T-W1 – Reference Manual
Version 1.02
www.acs.com.hk
Page 87 of 100
The authentication has to be performed in two steps. The first step is to send the Authentication
Certificate to the card. The second step is to get back two bytes of authentication data calculated by
the card.
Step 1:
Send Authentication Certificate to the Card.
Command Format (
abData
field in the
PC_to_RDR_XfrBlock
)
Pseudo-APDU
CLA
INS
P1
P2
MEM_L
CODE
KEY
CLK_CNT
Byte 1
Byte 2
……
Byte 5
Byte 6
FFh
84h
00h
00h
08h
Where:
KEY
Key to be used for the computation of the authentication certificate:
00h: Key 1 with no cipher block chaining
01h: Key 2 with no cipher block chaining
80h: Key 1 with cipher block chaining (SLE 5536 and SLE 6636 only)
81h: Key 2 with cipher block chaining (SLE 5536 and SLE 6636 only)
CLK_CNT
Number of CLK pulses to be supplied to the card for the computation of each bit
of the authentication certificate. Typical value is 160 clocks (A0h)
BYTE 1...6
Card challenge data
Response Data Format (
abData
field in the
RDR_to_PC_DataBlock
)
SW1
SW2
61h
02h
Where:
SW1 SW2
= 61 02h if no error, meaning two bytes of authentication data are ready. The
authentication data can be retrieved by
Get_Response
command
Step 2:
Get back the Authentication Data (
Get_Response
).
Command Format (
abData
field in the
PC_to_RDR_XfrBlock
)
Pseudo-APDU
CLA
INS
P1
P2
MEM_L
FFh
C0h
00h
00h
02h
Response Data Format (
abData
field in the
RDR_to_PC_DataBlock
)
CERT
SW1
SW2
Where:
CERT
16 bits of authentication data computed by the card. The LSB of BYTE 1 is