RFID PASSWORD MANAGEMENT METHODS FOR
FALSIFICATION PREVENTION IN BOOKSTORE
MANAGEMENT USING SECURE RFID TAGS
Yuichi Kobayashi, Yoji Taniguchi
Hitachi, Ltd., Systems Development Laboratory, 1099 Ohzenji, Asao, Kawasaki, Kanagawa, 215-0013, Japan
Toshiyuki Kuwana
Hitachi, Ltd., Tracing & Tracking Systems Division, 890 Kashimada, Saiwai, Kawasaki, Kanagawa, 212-8567, Japan
Masanori Akiyoshi
Graduate School of Information Science and Technology, Osaka University, 2-1
Yamada-oka, Suita, Osaka, 565-0871, Japan
Keywords: RFID, falsification prevention, risk analysis.
Abstract: The receipt data on radio frequency identification (RFID) tags attached to books may be used to prevent
shoplifting in bookstores. To protect the receipt data, it is important to manage the passwords of RFID tags.
We use Secure RFID tags, which protects data with an RFID password, for preventing falsification of RFID
data. We also propose ten methods that manage RFID passwords from the point of the phases of RFID
passwords and the ways a password is associated with a Secure RFID tag. We analyze and compare these
methods using fault tree analysis. We show that our proposed RFID passwords management methods are
effective in preventing falsification for resale.
1 INTRODUCTION
The shoplifting of books is a serious problem in
Japan. A report says that there are many shoplifted
books for resale. The publishing industry in Japan is
examining a method for attaching an RFID tag to
books, which records receipt data on the RFID tag
memory. However, there is a risk of someone
reselling a shoplifted book to a second-hand
bookstore, after illegally overwriting the receipt data
in the RFID tag. So a method for protecting the data
in the RFID tag is needed.
There are several methods that mount hash logic
on an RFID tag and authenticate the user to protect
the RFID data (Weis 2003; Engberg, Harning &
Jensen 2004; Tripathy & Nandi 2006). However,
these methods are not realistic in a situation in which
an RFID tag is attached to a book because mounting
advanced calculation logic on an RFID tag requires
a larger IC chip, which increases the cost of the
RFID tag.
Secure RFID tags are low cost RFIDs. This type
of RFID tag protects data using a simple password
authentication method. We chose to use Secure
RFID tags because these tags are smaller, cost less,
and suitable for attaching to books. It is very
important to manage an RFID password when using
Secure RFID tags. Therefore we propose ten
methods for managing RFID passwords. We analyze
their security, and show that they are effective in
preventing falsification.
2 BOOK MANAGEMENT
SYSTEM WITH SECURE RFID
TAGS
In this chapter, we describe the book management
system with Secure RFID tags in a bookstore
environment.
447
Kobayashi Y., Taniguchi Y., Kuwana T. and Akiyoshi M. (2008).
RFID PASSWORD MANAGEMENT METHODS FOR FALSIFICATION PREVENTION IN BOOKSTORE MANAGEMENT USING SECURE RFID TAGS.
In Proceedings of the International Conference on e-Business, pages 447-453
DOI: 10.5220/0001908504470453
Copyright
c
SciTePress
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Bookstore
Forward Logistics
Secondhand
Bookstore
Publisher
Distributor
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ISBN and
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Stock
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ISBN and
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Sold
Sold
Consumer
Write “Stock at the
time of arrival.
Write “Sold” at the
time of sale.
Check for “Sold”
when buying the book.
DeleteStock” when
the book is returned.
Reverse Logistics
Secure RFID memory
Figure 1: Shoplifter prevention method.
2.1 Book Distribution Procedure for
Preventing Shoplifting
The publishing industry in Japan is considering a
method for preventing shoplifting by using Secure
RFID tags. Figure 1 shows the procedure for
preventing shoplifting in a book distribution. First, a
bookstore writes in “Stock” onto the Secure RFID
tag when a book arrives from a distributor. This
denotes the state before being sold. Next, when a
consumer buys the book, the bookstore changes
“Stock” to “Sold” in the Secure RFID tag. At the
entrance of the store, the security system reads the
data on the Secure RFID tags to check if the book
was purchased. Finally, when a second-hand
bookstore buys a book from a consumer, it checks
whether the book’s Secure RFID tag reads “Sold” or
“Stock”. Not only bookstores, but second-hand
bookstores cooperate with the publishing industry.
All the companies relevant to book publishing and
selling can examine the system to counter the
shoplifting problem.
In order for this system to work, the data of the
Secure RFID tag must not be able to be easily
rewritten from “Sold” to “Stock”. Rewriting
information should be done with an access control
function with a password of the Secure RFID tag.
2.2 An Existing RFID Passwords
Management Method
Figure 2 shows the RFID password management
system for a bookstore.
Operation 1: When the book arrives, the book’s
code written in the Secure RFID tag is read, and the
pre-arrival data is checked. After it is checked, the
book code is input into the server with the arrival
data. Then, the date of arrival, bookstore code,
“Stock”, etc... are written onto the Secure RFID tag.
An RFID password is then set up for the Secure
RFID tag, and the memory is locked using that
password.
Operation 2: When the book is sold, the book code
in the Secure RFID is read, the price is checked, and
the sale information is input into the server. At this
time, the memory of the Secure RFID tag is
unlocked by using the RFID password, and “Sold” is
rewritten onto the Secure RFID tag. Finally, the
memory is locked again by using the password.
ICE-B 2008 - International Conference on e-Business
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BOOKSTORE
BOOKSTORE
only read data
Surveillance
read data and
write new data
using the tag
password
Sale of books
read data and
set up a tag
password
Arrival of books
1
2
3
Handy
Interrogator
Handy
Interrogator
Fixed
Interrogator
Fixed
Interrogator
Gate
only read data
Returned books
4
Figure 2: System using the Secure RFID tags in the bookstore.
Operation 3: A gate type interrogator system at the
entrance is set up, and the interrogator checks if
“Sold” or “Stock” is written on the Secure RFID tag.
Operation 4: If the book is returned, the memory of
the Secure RFID tag is unlocked by using the RFID
password, and all data from the bookstore and the
password are deleted. Afterwards, the returned
book’s information is input into the server.
The publishing industry in Japan tries to manage
RFID passwords by using identical passwords in all
bookstores, and applies the RFID password
management method for each bookstore. This
method has the advantage of being less expensive;
however, if one RFID password is stolen, all Secure
RFID tags are compromised. The possibility of
information being falsified on the Secure RFID tags
attached to books stocked in all bookstores is high.
Therefore, the distinction between a shoplifted book
and a legally bought one becomes difficult in a
second-hand bookstore, and the effect of preventing
theft by using the Secure RFID tag weakens. It is
necessary to manage RFID passwords more
carefully.
3 RFID PASSWORDS
MANAGEMENT METHODS
We propose ten methods for managing not identical
RFID passwords but different passwords so that the
risk after a password is stolen will be lessened. It is
effective to divide RFID passwords into groups to
manage different RFID passwords. For example, the
group includes an inspection interrogator, a book,
etc… Moreover, because it is usually impossible to
read the RFID password set in the Secure RFID tag,
it is necessary to set the RFID tag with an RFID
password beforehand. Therefore, we present ten
methods which can be used to manage RFID
passwords from the point of a phase of RFID
password management and the ways in which a
password is associated with a Secure RFID tag.
Figure 3 shows the relationship between the phase of
RFID passwords, and the ways passwords are used
for a Secure RFID. There are four phases of RFID
password management, (1) each bookstore, (2) each
inspection interrogator system, (3) each arrival, and
(4) each book. On the other hand, there are (a) the
way of using a conversion table, (b) the way of using
operation logic, and (c) the way of updating a key.
We define the combination of phases of RFID
passwords and the ways a password is used for a
Secure RFID tag as the RFID password management
methods.
3.1 Phases for Managing RFID
Passwords
A bookstore that manages RFID passwords
separately by each group lessens the risk of RFID
tag falsification more than a bookstore that manages
identical RFID passwords. We explain the phases
for managing RFID passwords as follows.
RFID PASSWORD MANAGEMENT METHODS FOR FALSIFICATION PREVENTION IN BOOKSTORE
MANAGEMENT USING SECURE RFID TAGS
449
each
interrogator
each
interrogator
identical
identical
each
bookshop
each
bookshop
each
book
each
book
existing method
each
arrival
each
arrival
conversion
table
operation
logic
update
electronic key
conversion
table
operation
logic
update
electronic key
conversion
table
operation
logic
update
electronic key
(1)
(2)
(3)
(4)
(a) (b) (c)
(a) (b) (c)
(a)
(b) (c)
Figure 3: Classification of Password Management Methods.
(1) Each bookshop: Manage the different RFID
passwords in each bookstore. Each bookstore
decides and manages an RFID password.
(2) Each interrogator system: Manage the
different RFID passwords in each interrogator
system in a bookstore when the book arrives.
Each interrogator sets up an RFID password
and an interrogator’s ID to the Secure RFID
tag attached to the newly arrived book.
(3) Each interrogator system and arrival: Manage
the different RFID passwords in each
interrogator system in a bookstore when the
book arrives and update the RFID passwords
each time books arrive. Each interrogator
system sets up an RFID password, an
interrogator’s ID, and the arrival date to the
Secure RFID tag.
(4) Each book: Manage the different RFID
passwords in each Secure RFID tag attached
to the book. The bookstore associates the
RFID password with a unique ID that
identifies the Secure RFID tag.
It is possible to manage the different RFID
passwords in each title of the book. However, the
titles with only one book in stock accounts for 70%
of the inventory in most bookstores. Therefore, we
omit the explanation for each title here because each
title and each book are almost the same.
3.2 Ways in which RFID Passwords
are Associated with a Secure RFID
Tag
When a different RFID password is set to a Secure
RFID tag, the system should associate that password
with that Secure RFID tag. We explain the ways in
which this is accomplished.
(a) Conversion table: The system generates the
RFID password at random, and associates the
RFID password with the interrogator’s ID,
arrival date, or a unique ID written to the
Secure RFID tag to identify the phase of RFID
password management.
(b) Operation logic: Use operation logic with an
electronic key. The system generates an RFID
password by calculating data, such as the
interrogator’s ID, arrival date, or a unique ID
written to the Secure RFID tag (Kobayashi,
Kuwana, Taniguchi & Komoda 2007).
(c) Update electronic key: Periodically update the
electronic key used in (b).
4 SECURITY EVALUATION OF
RFID PASSWORD
MANAGEMENT METHODS
In this chapter, we show the results form a fault tree
analysis (FTA) of the RFID password management
methods, and compare those analysis results.
ICE-B 2008 - International Conference on e-Business
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(B-12) A password
will be decoded by
ha cking
(C-1) An
interrogator
will be stolen
(C-2) Can falsify
sales data using the
stolen interrogator
RFID data will be falsified,
and resal e of the book will
be successful
(B-2) Can falsify
sales data using a
stolen password
B C
A
0.3%
4.1%
B-1
(B-11) Can falsify sales
data using a password
stolen at another bookstore
Figure 4: FTA of shoplifting a book.
4.1 Fault Tree Analysis of RFID
Passwords Management Methods
We analyzed the security performance of the RFID
password management method, which combined the
phase of an RFID password and the ways in which
the password is associated with a Secure RFID tag
described above, using FTA.
We know that the probability of a successful
falsification of RFID data for resale is low; the RFID
password management method will have a high
security performance. Therefore, let a top event of
FTA be the probability that the RFID data of a
shoplifted book will be falsified, and resale of the
book will be successful in one month. Moreover, it
is necessary to decipher the RFID password of the
Secure RFID tag so that someone may falsify the
RFID data. There are two effective attacks for
deciphering an RFID password. The first is that
someone illegally uses a common interrogator and
hacks into the Secure RFID tag like brute force
attack. The second attack is that someone steals and
illegally uses the handy interrogator of the bookstore.
The FTA is shown in Figure 4. The probability of
each event of FTA is explained below.
(B-11): This event is the probability of falsifying the
RFID data of a bookstore using the RFID
password stolen at another bookstore. In the
existing RFID password management method,
this probability P
B-11
is 100% because an
RFID password is identical at all the
bookstores. In the proposed RFID password
management method, this probability P
B-11
is
0% because the RFID passwords at least differ
for each bookstore.
(B-12): This event is the probability that an RFID
password will be decoded in one month by
hacking into a Secure RFID tag. This
probability P
B-12
was obtained from the
following expression.
(
)
%1.41
12
=
=
TimeEmonthP
B
(1)
E (Time) is an expected time spent on the
hacking attack. The time that a Secure RFID
tag is checked whether one password is right
using one interrogator is assumed to be about
30 milliseconds and the length of the Secure
RFID password is assumed to be 32 bits
according to the specification of Secure RFID.
(B-2): This event is the probability of falsifying
sales data on a Secure RFID tag in one month
using a common interrogator. This probability
depends on the number of books that can be
falsified using a decoded RFID password.
This probability P
B-2
is 100% in the case of the
existing method or “(1) each bookstore”
because all RFID passwords in the bookstore
are the same. In the case of “(2) each
interrogator”, this probability P
B-2
is 33%
when there are three interrogators for
inspection is three. In the case of “(3) each
interrogator and arrival”, this probability P
B-2
was obtained by the following expression.
%271
2
=
×
=
BNABNINP
B
,
(2)
where IN denotes the number of the
interrogators for inspection, ABN denotes the
number of applicable stocked books, and BN
denotes the number of stocked books. The
applicable stocked book means the books that
remain unsold for one month because the
RFID PASSWORD MANAGEMENT METHODS FOR FALSIFICATION PREVENTION IN BOOKSTORE
MANAGEMENT USING SECURE RFID TAGS
451
0.1
1
10
100
conversion table
operation logic
update electronic key
identical
each
b
ookstor
e
each
interro
g
ato
r
each
interrogato
r
& arriva
l
each
b
oo
k
falsification risk (%)
Figure 5: Relationship between the management phases and the falsification risk.
decoded RFID password is associated with
those books. IN is assumed to be three and
ABN/BN is assumed to be 0.79 because the
merchandise turnover is about 17%, and the
update frequency of the RFID passwords is
once a week. In the case of “(4) each book”,
this probability P
B-2
is 1% when the number of
books stolen in one month in one store is 100,
because the number of books that can be
falsified by using the decoded RFID password
is only one.
(C-1): This event is the probability that an
interrogator will be stolen from a bookstore in
one month. Here, this probability P
C-1
is
assumed to be 0.3%.
(C-2): This event is the probability of falsifying
sales data on a Secure RFID tag in one month
using the stolen interrogator. This probability
depends on the ways in which an RFID
password is associated with a Secure RFID tag.
In the case of “(a) conversion table”, this
probability depends on the managing phase of
RFID passwords because the conversion table
is contained in the interrogator of the
bookstore. This probability P
C-2
is 100% in the
case of “(1) each bookstore”, 33% in the case
of “(2) each interrogator” or 27% in the case
of “(3) each interrogator and arrival”, as well
as in the case of the (B-2) event. In the case of
“(4) each book” this probability P
C-2
is 76%
because the merchandise turnover is about
17% and the update frequency of the RFID
passwords is once a day. In the case of “(b)
operation logic”, this probability P
C-2
is 100%
because the operation logic is contained in the
interrogator of the bookstore. In the case of
“(c) update electronic key”, this probability
can be estimated at 80% when changing the
key once a week.
The result of FTA for each RFID password
management method is shown in Table 1. The RFID
password management methods below from “(1)
each bookstore” is classified into the phases of RFID
password management and the ways in which an
RFID password is associated with a Secure RFID
tag. The falsification risk in Table 1 is the
probability that falsification of the RFID data for
resale will be successful. This falsification risk is
low because the security of the method is high.
4.2 Comments of the Results of FTA
Figure 5 shows the probability that a falsification
will be successful for each RFID password
management method. This figure also shows that the
difference between the phases of RFID password
management is larger than the difference between
the ways in which a password is associated with a
Secure RFID tag. We found that it is better to
manage RFID passwords in several phase. Moreover,
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452
all the RFID password management methods are
effective in preventing falsification for resale
because the highest probability that falsification will
be successful for “(1) each bookstore” is 4.25% for
all the methods.
Table 1: Comparison of the security risk for each RFID
password management method.
RFID passwords
management method
Falsification
Risk
Identical 100.00 %
(1) Each bookstore 4.25 %
(a) Conversion
table
(2) Each interrogator 1.42 %
(3) Each interrogator
& arrival
1.13 %
(4) Each book 0.24 %
(b) Operation
logic
(2) Each interrogator 1.58 %
(3) Each interrogator
& arrival
1.31 %
(4) Each book 0.30 %
(c) Update
electronic key
(2) Each interrogator 1.53 %
(3) Each interrogator
& arrival
1.26 %
(4) Each book 0.25 %
5 CONCLUSIONS
We proposed methods that use Secure RFID tags
and RFID password management for preventing
falsification of RFID data in book distribution.
These proposed methods were explained by the
point of phases of RFID passwords, and the ways in
which a password is associated with a Secure RFID
tag. We showed that these methods decreased the
probability of falsification to about 5% or less in this
situation. These results are useful for RFID
password management in bookstores.
ACKNOWLEDGEMENTS
This paper is based on the achievement of a
Japanese National Research and Development
Project, the “Secure RFID Project” that was
conducted by METI (Ministry of Economy, Trade,
and Industry) for the eight months from August
2006 to March 2007.
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Identification Devices’, Masters Thesis, Massachusetts
Institute of Technology.
Engberg, SJ, Harning, MB & Jensen, C 2004, ‘Zero-
knowledge device authentication: Privacy and security
enhanced RFID preserving business value and
consumer convenience’, in the Second Annual
Conference on Privacy, Security and Trust (PST'04),
pp.89-101
Tripathy, S & Nandi, S 2006, ‘Robust Mutual
Authentication for Low-cost RFID Systems’, in 4th Int.
IEEE Conf. Industrial Informatics (INDIN’06),
pp.949-954.
Kobayashi, Y, Kuwana, T, Taniguchi, Y & Komoda, N
2007, ‘Group Management System of RFID
Passwords for Item Life Cycle’, in Emerging
Technologies and Factory Automation (ETFA 2007),
pp.884-887.
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MANAGEMENT USING SECURE RFID TAGS
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