Vision and Challenges for Realising the Internet of Things

3.1 Authentication Features
For each type of product, such as pharmaceuticals, plane spare parts, or luxury goods, appropriate
tags that comply with the manufacturing processes have to be identified or developed.
Different aspects of the product packaging and product materials need to be considered. A
wide range of products from several vendors are available. A key challenge is the integration of
the tags into real life products. Factors to consider include cost, durability, reading speed,
information capacity, and of course security.
As an example, consider an RFID tag that was developed within the SToP project to fit into the
metal casing of a watch (Figure 4.1-1). The main challenge was to be able to reliably scan the
tag through the metal casing while meeting the watch maker’s requirements. In particular,
there was a strong need to increase the reading distance of the RFID tag in a metallic environments.
Figure 4.1-1: RFID tag embedded in the casing of a watch
Necessary adjustments of manufacturing processes to enable production of tagged products
were investigated together with industry partners. The results of this task have been found to
be an important factor for the real-world applicability of the concepts. Here, new requirements
imposed by the utilized smart tags, such as maximum pressure or temperature, have
been taken into consideration.
RFID is a wireless technology designed for automatic identification – and potentially a very
effective one. Each RFID tag carries a unique identifier that can be captured with a reading
device without requiring a line of sight, which makes it an appealing technology that can replace
barcodes in many areas. However, standard RFID tags cannot be considered secure as it
is technically feasible to clone RFID tags. Therefore, the uniqueness of an identifier cannot be
guaranteed. Thus in the strict sense, standard RFID tags are not suitable as a tool for authentication.
This weakness can be overcome by linking an RFID identifier with an online database,
where the current status of an identifier is kept. Only if this status is valid in the current
context, the item carrying the respective tag should be considered authentic.
There are developments under way that extend the standard functionality of RFID tags by
secure authentication mechanisms that rely on a challenge/response protocol between the
reader and the tag. The basic idea is that the tag is accepted as being genuine if and only if it
responds correctly to a challenge given by the reader. The response depends on a secret key
which is stored in the tag, and on a cryptographic algorithm. This however, requires more
elaborate capabilities from such tags, such as securely storing the key and performing a cryptographic
calculation, which increases their cost.
Due to their low cost, printed features are highly attractive as security features. One example
is the “copy detection pattern” (CDP), which is a random-looking pattern of small dots that
can be printed with any printing technology. Within the pattern, information such as a serial
number can be encoded. The trick however is the fact that it is impossible to create a copy of
this pattern that would be accepted as the original pattern. Since each scan/print cycle creates
small deviations within the pattern, a statistical analysis of the pattern reveals the fact that it is
a duplicate. However, the use of CDPs requires an extensive knowledge of printing technologies
and they are not a “plug and play” solution.
Both technologies, RFID and printed features, have distinctive advantages and drawbacks. In
general, RFID tags need not be visible and therefore they neither require dedicated space on a
packaging nor do they disturb the visual appearance of an item. They can be covered by a layer
of material and are thus protected against environmental forces. However, achieving high
reading rates of RFID tags is still a subject to engineering challenges regarding tag integration
and reader installation. In contrast, printed features are very cheap to produce and provide a
high level of protection against cloning. The devices that can read tags, either RFID or printed,
are widely available, for example in mobile phones. Some models include RFID readers, and
CERP-IoT – Cluster of European Research Projects on the Internet of Things
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