NT3H2211W0FHKH Datasheet, PDF (36/77 Pages) NXP Semiconductors – NTAG I2C plus, NFC Forum Type 2 Tag compliant IC with I2C interface

NXP Semiconductors
NT3H2111/NT3H2211
NFC Forum Type 2 Tag compliant IC with I²C interface
8.7 Password authentication
The memory write or read/write access to a configurable part of the memory can be
constrained to a positive password authentication. The 32-bit secret password (PWD) and
the 16-bit password acknowledge (PACK) response shall be typically programmed into
the configuration pages at the tag personalization stage.
The AUTHLIM parameter specified in Section 8.3.11 can be used to limit the negative
authentication attempts.
In the initial state of NTAG I²C plus, password protection is disabled by an AUTH0 value of
FFh. PWD and PACK are freely writable in this state. Access to the configuration pages
and any part of the user memory can be restricted by setting AUTH0 to a page address
within the available memory space. This page address is the first one protected.
For a comprehensive description of all protection mechanism refer to Ref. 9.
Remark: The password protection method provided in NTAG I²C plus has to be intended
as an easy and convenient way to prevent unauthorized memory accesses. If a higher
level of protection is required, cryptographic methods can be implemented at application
layer to increase overall system security.
8.7.1 Programming of PWD and PACK
The 32-bit PWD and the 16-bit PACK need to be programmed into the configuration
pages, see Section 8.3.11. The password as well as the password acknowledge are
written LSByte first. This byte order is the same as the byte order used during the
PWD_AUTH command and its response.
The PWD and PACK bytes can never be read out of the memory. Instead of transmitting
the real value on any valid read command from both - NFC and I²C - interface, only 00h
bytes are replied.
If the password authentication is disabled, PWD and PACK can be written at any time.
If the password authentication is enabled, PWD and PACK can be written after a
successful PWD_AUTH command only.
Remark: To improve the overall system security, it is advisable to diversify the password
and the password acknowledge using a die individual parameter of the IC, which is the
7-byte UID available on NTAG I²C plus.
NT3H2111/NT3H2211
Product data sheet
COMPANY PUBLIC
All information provided in this document is subject to legal disclaimers.
Rev. 3.0 — 3 February 2016
359930
© NXP Semiconductors N.V. 2016. All rights reserved.
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