Specifications of the HT2 MOA3 S20

Rev. 1.1

1997-08-19

Ht2moa3.doc/HS

Page 17 of 22

5.4 Definition of Passwords and Keys

Keys are cryptographic codes, which determine data encryption during data transfer between

read/write device and transponder. They are used to select a HITAG 2 transponder in 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/write device.

Passwords are needed to select a HITAG 2 transponder in Password Mode. There is one pair of

passwords (Password TAG, Password RWD) which has to be identical both on the transponder

and the read/write device.

Password TAG:

Password that the transponder sends to the read/write device and which

may be verified by the latter (depending on the configuration of the

read/write device).

Password RWD:

Password that the read/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/write device and on the transponder have to be identical pairs.

HITAG 2 in Password mode:

on the

read/write

device

on the

transponder

Password RWD

⇔ Password RWD

as an option (depending on the configuration of the read/write device):

Password TAG

⇔ Password TAG

HITAG 2 in Crypto mode:

on the

read/write

device

on the

transponder

KEY LOW

⇔

KEY LOW

KEY HIGH

⇔

KEY HIGH

as an option (depending on the configuration of the read/write device):

Password TAG

⇔ Password TAG

The passwords and keys are predefined by Philips Semiconductors by means of defined Transport

Passwords and a Transport Key. They can be written to, which means that they can be changed

(see also Chapter “Configuration of Delivered HITAG 2 Transponders“).

ATTENTION: Passwords and Keys only can be changed if their current values are known!