2001 Oct 01

8

Philips Semiconductors

Product specification

HITAG 2 stick transponder

HT2DC20S20

Definition of keys and passwords

Keys are cryptographic codes, which determine data

encryption during data transfer between the read and write

device and the transponder. They are used to select a

HT2DC20S20 transponder in the crypto mode. The 16-bit

key HIGH and 32-bit key LOW form one 48-bit key which

has to be identical on both the transponder and the read

and write device.

Passwords are needed to select a HT2DC20S20

transponder in the password mode. There is one pair of

passwords (password TAG and password RWD) which

has to be identical both on the transponder and the read

and write device:

• Password TAG

Password that the transponder sends to the read and

write device and which may be verified by the latter

(depending on the configuration of the read and write

device).

• Password RWD

Password that the read and write device sends to the

transponder and which is checked for identity by the

latter.

It is important that the following values are in accordance

with each other, i.e. the respective data on the read and

write device and on the transponder have to be identical

pairs.

The keys and passwords are predefined by Philips by

means of defined transport passwords and a transport

key. They can be written to memory, which means that

they can be changed (see also Section “Configuration of

delivered transponders”).

Remark: keys and passwords only can be changed if their

current values are known!

Table 5

Keys and passwords for the read and write device and the transponder

Note

1. Optional for both password and crypto mode; depending on the configuration of the read and write device.

Configuration of delivered transponders

HT2DC20S20 transponders are delivered with the following configuration.

Table 6

Configuration of delivered transponders

Note

1. Before delivering transponders to end users, pages 1 to 3 should be locked by setting configuration byte: set bit 6 to

logic 1 for page 3 and set bit 7 to logic 1 for pages 1 and 2.

MODE

ON THE READ AND WRITE DEVICE

ON THE TRANSPONDER

Password mode

password RWD

⇔

password RWD

Crypto mode

key LOW

⇔

key LOW

key HIGH

⇔

key HIGH

−

password TAG; note 1

⇔

password TAG

ITEM

NAME

VALUE

DESCRIPTION

REMARK

Unique serial number

serial number

0xXXXX

read-only

fixed

Configuration

configuration byte

0x06

password mode;

Manchester code;

pages 1 to 7 read/write

can be changed;

note 1

Transport passwords

and transport keys

password RWD

0x4D494B52

MIKR

password TAG

0xAA4854

key LOW

0x4D494B52

MIKR

key HIGH

0x4F4E

ON