978-1-4673-7682-2/15/$31.00 ©2015 IEEE 2608
2015 12th International Conference on Fuzzy Systems and Knowledge Discovery (FSKD)
A Variant of Schnorr Signature Scheme for
Path-Checking in RFID-based Supply Chains
Wei Xin, Meilin Wang, Shuai Shao
China Information Technology Security Evaluation Center
Beijing, China
Email: xinwei@pku.edu.cn
Zhao Wang, Tao Zhang
Institute of Software, EECS, Peking University
Beijing, China
Email: xinwei@pku.edu.cn
Abstract—The RFID technology has attracted considerable
attention in recent years, and brings convenience to supply chain
management. In this paper, we concentrate on designing path-
checking protocols to check the valid paths in supply chains. By
entering a valid path, the check reader can distinguish whether
the tags have gone through the path or not. Based on modified
schnorr signature scheme, we provide a path-checking method
to achieve multi-signatures and final verification. In the end, we
conduct security and privacy analysis to the scheme.
Keywords—RFID; schnorr signature; path-checking; supply
chain
I. INTRODUCTION
Today, RFID technology is a fundamental infrastructure in
the information technology. RFID systems consist of readers
and tags, and sometime a back-end server. Readers use radio
signals to automatically identify objects which were equipped
with RFID tags .Readers can also access the data stored in
tags.
RFID systems have security and privacy related problems
such as eavesdropping, tracking and relay attacks . The RFID
security and privacy challenge is formidable mainly because
of the extremely scarce resources available on a typical tag.
Only simple operations are allowed such as XOR, bit inner
product, pseudorandom number generator (PRNG) and hash
function. Much efforts has been made to design lightweight
authentication protocols based on these fundamental elements.
Among which, PRNG is considered to be an essential part to
construct privacy-preserving protocols.
A supply chain moves a product or service from supplier to
customer. With the deployment of RFID technologies which
provide rich and timely information, supply chain management
process has been significantly improved. To track RFID-based
products in supply chains recently become a hot topic in RFID
application. The tags are attached to some products and go
through a special path in a supply chain. The path consists
of a list of steps. Typically, we need to guarantee that the
products pass through the right path as it was supposed to for
quality assurance. The Fig. 1 illustrates path-checking process.
At the beginning, the issuer(I) do preparations for tags, while
attaching a tag T
i
to a product. T
i
then pass through a series of
steps and will be marked at each one of readers. In the end,
the checker will interact with the tags being able to verify
whether, according to some data stored in the tags, they go
through the valid path. The target of an adversary in such a
scheme is to either produce a phony tag or make a genuine
tag which followed a different path that passes the verification
of the checking reader. Meanwhile, an adversary should not
be able to recognize or trace tags during the flow steps in the
supply chain.
Fig. 1. Path checking in supply chain
We organized the rest of the paper as follows. In Section 2,
related works were introduced concerning RFID privacy and
path-checking issues in RFID systems. Section 3 describes
informally the proposed scheme in supply chain. Sections
4 demonstrates security and privacy analysis. And finally,
Section 5 concludes.
II. RELATED WORK
A. RFID privacy
RFID privacy is one of the areas which are most discussed in
recent years. Without lose of generality, there are two kinds of
privacy in RFID system: one is called tag anonymity. It means
an adversary A should not be able to get the real identity of
tags he interacts with. The second is named untraceability:
an adversary A should not be able to trace or track the
person(product) attached with tags by a fake reader. There
is a special untraceability named forward untraceability (also
known as forward privacy), that is, an adversary getting the
tags secret cannot correlate the tag with its responses before
the last protocol run with a valid reader [1].
A great number of privacy-preserving RFID protocols have
been proposed in the literature, Juels offers a survey of