ib technology

8

For READ and WRITE commands a second security check is automatically performed

by mutually exchanging two Passwords between the RWD and the Hitag2 tag. If the

PASSWORD exchange operation is successful then memory access is allowed and the

READ and WRITE commands can proceed.

The first password is four bytes long (32 bits) and is called the "RWD PASSWORD"

which is located at page 1 in the tag memory. The second password is three bytes long

(24 bits) and is called the "TAG PASSWORD". It is located at page 3 in the tag from the

second to the forth byte, the first byte in page 3 is the tag configuration byte which

controls the basic mode of operation. This should be left as 06 (hex) until the system is

fully understood. The configuration byte bit definitions are described at the end of this

document.

The RWD and TAG PASSWORDS are also stored in the Micro RWD EEPROM to

allow the reader to verify the tag, and the tag to mutually verify the reader.

For READ and WRITE commands the Micro RWD reader sends the RWD

PASSWORD to the H2 tag first, which then checks this code against it’s own RWD

PASSWORD. If they agree then the H2 tag sends it’s TAG PASSWORD to the reader

which then checks the code against it’s stored TAG PASSWORD. If they agree then the

second security level has been passed and the READ/WRITE commands can proceed.

The use of these two levels of security makes the Hitag 2 tags very suitable for secure

data storage or for RF identification applications such as locks and access control.

Hitag 2 Memory Map (PASSWORD mode)

The memory of the Hitag 2 transponder consists of 256 bits of very low power

EEPROM memory which is organised into 8 pages of 32 bits (4 bytes) each.

Page No.

Content (32 bit words/ 4 bytes)

0

Serial number

1

Password RWD

(Default = “MIKR” = 4D 49 4B 52 hex)

2

Reserved

3

8 bit Configuration, 24 bit Password TAG (Default = 06 AA 48 54 hex)

4

Read/Write page

5

Read/Write page

6

Read/Write page

7

Read/Write page