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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Trusted Tiny Things: Making Devices in Smart Cities More Transparent</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Stanislav Beran</string-name>
          <email>s.beran@abdn.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Edoardo Pignotti</string-name>
          <email>e.pignotti@abdn.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Peter Edwards</string-name>
          <email>p.edwards@abdn.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Computing Science &amp; dot.rural Digital Economy Hub , University of Aberdeen</institution>
          ,
          <addr-line>Aberdeen AB24 5UA</addr-line>
          ,
          <country country="UK">UK</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>In this demo we present the Trusted Tiny Things system that can be used to interrogate Internet of Things (IoT) devices and present users with information about their characteristics and capabilities. The system consists of a mobile application used to retrieve information about IoT devices supported by RESTful web services. In order to infer IoT device capabilities our services perform reasoning over the provenance of devices characterised using a number of Semantic Web technologies. In this demo we illustrate the use of the system with two distinct IoT devices: an NFC tag used at bus stops to provide a means to access real-time bus timetables, and a black box device installed into vehicles by insurance companies to track driving behaviour.</p>
      </abstract>
      <kwd-group>
        <kwd>internet of things</kwd>
        <kwd>provenance</kwd>
        <kwd>transparency</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>
        The vision of the Internet of Things (IoT) is a dynamic global network based on
standard and interoperable communication protocols where physical and virtual
`things' have identities, physical attributes, and capabilities and are seamlessly
integrated into the existing internet infrastructure. The IoT is thus built upon
a range of sensors and other devices [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] that together represent the `things'.
These devices range from passive radio tags to internet connected sensor
platforms and embedded computers. Deployments of such devices are increasingly
commonplace in Smart City environments to capture, analyse and exchange
streams of information. For example, passive NFC (Near Field Communication)
tags are currently in use by Aberdeenshire Council in Scotland UK to provide
smartphone access to timetable information for a particular bus stop. Active IoT
devices include in-car black boxes [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] being introduced by insurance companies
to assess the behaviour of drivers and a ect their premiums. Such devices and
their associated entities (e.g. web services or other devices in the IoT ecosystem)
could potentially generate vast amounts of data. This data may contain personal
or any other con dential data that users may not wish to share. Alternatively,
user may wish to know how the data is used and by whom.
      </p>
      <p>
        Questions that a user might ask include: What kind of data does the thing
collect? Is the data transmitted? If so, how and to whom? For what purposes are
the data used? What control do I have over any aspects related to the generation
and use of this data?. These questions are re ected in the \TRUSTe Internet of
Things Privacy Index - GB Edition1" study where more than 80% of the 2,005
people interviewed were concerned about such issues. Our proposed solution is
largely based on participatory design activities we conducted during the course of
the project. To date, we have conducted a number of participatory design events
involving a total of 77 participants with di erent technological backgrounds[
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>
        These questions are particularly relevant in the context of Smart City
development. Bartoli et al.[
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] identi ed privacy and sensitive data management as one
of the key issues to be addressed during the design of Smart City systems. The
authors discuss the di erent perspectives to be taken when assessing security
or insecurity of a particular service and highlight that service should be con
gurable to best suit speci c user needs based on sensitive data the user provide.
Bartoli et al. also state: \The number of users, and the volume and quality of
collected data, will also increase with the development of Smart Cities. When
personal data is collected by smart meters, smart phones, connected plug-in
hybrid electric vehicles, and other types of ubiquitous sensors, privacy becomes all
the more important. The challenge is, on the one hand, in the area of identity
and privacy management, where, for instance, pseudo-nomination must be
applied throughout the whole system, in order to separate the data collected about
a user (which is required in order to provide high- quality personalised services)
from the users real identity (which is required for purposes such as
accounting); this includes that the usage of addressing identi ers, such as IP or MAC
addresses, for the purpose of identi cation must be avoided in future systems."
      </p>
      <p>
        The Trusted Tiny Things (T3) project is investigating how Semantic Web
technologies can be used to describe the context surrounding IoT devices (e.g.
manufacturer, owner, security method) and to reason about device capabilities.
As 'things' become more interconnected this context should also include
provenance information: a record of the entities (devices or services) and processes
(data transmission, data analysis, decision making) involved in the creation and
use of data. A formal representation of provenance has been identi ed as
essential to support users (and machines) to better understand and trust data[
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. For
example, in the car black box scenario, provenance could be used in order to
understand what kind of data the box is collecting, what agents or services are
using this data, and for what purpose.
      </p>
      <p>In the remainder of this paper we discuss our T3 software system and the
supporting semantic framework. We conclude by presenting a list of features
being demonstrated about the system through the use of two case studies
(incar black box and bus stop).</p>
      <sec id="sec-1-1">
        <title>1 https://www.truste.com/gb-internet-of-things-index-2014/</title>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>The Trusted Tiny Things Architecture</title>
      <p>We have developed a software infrastructure and mobile app (see Figure 2) that
can be used to query, update and register IoT devices and to notify the user of
any changes in the capabilities of a registered device.
2.1</p>
      <sec id="sec-2-1">
        <title>User Groups</title>
        <p>There are two user groups concerned with usage of our system.
{ Device owners and manufacturers - this user group is concerned with
registering IoT device into the system and updating device characteristics
and provenance records through our Restful API according to our
guidelines2.
{ Users of the IoT system (devices and services) - These are the users
of the IoT device and associated services and they interact with our system
through NFC-enabled Android mobile application.
2.2</p>
      </sec>
      <sec id="sec-2-2">
        <title>System Architectural Layers</title>
        <p>The system is composed of multiple layers (see Figure 1):
{ Storage layer - it is used for storing and retrieving device metadata,
provenance record and information about users. We are using two di erent Jena
TDB3 repositories. One repository holds publicly available provenance of IoT
devices. The other repository holds a record of user preferences and accepted
devices. We also utilise MySql Database to store con dential user data for
increased security(e.g smartphone IDs used to identify users, associations
with the IoT devices and statistics how users are using our system).
{ Ontological layer - it contains a number of ontologies used to support the
metadata in the Storage layer. These ontologies are discussed in Section 3.
{ Service Layer - it de nes methods for querying, updating, and
synchronising data from the devices. It is also capable of notifying users of any changes
in an IoT device or service (e.g. a new organisation is using information
provided by an existing IoT device).
{ RestFul API Service Layer - it provides uniform access to the system
from external applications such us our Trusted Tiny Things mobile app.
2.3</p>
      </sec>
      <sec id="sec-2-3">
        <title>Core Services</title>
        <p>The system consists of ve core Java EE based services:</p>
        <sec id="sec-2-3-1">
          <title>2 http://t3.abdn.ac.uk/guidelines</title>
        </sec>
        <sec id="sec-2-3-2">
          <title>3 http://jena.apache.org/documentation/tdb/</title>
          <p>Service Layer
Ontology Layer
Storage Layer</p>
          <p>RESTful API Services
Notification</p>
          <p>Capability Reasoning</p>
          <p>Register
T3 Annotations and Capabilities</p>
          <p>W3C PROV</p>
          <p>Jena TDB</p>
          <p>IoT Device Provenance
User Accepted Capabilities and</p>
          <p>Preferences</p>
          <p>Update</p>
          <p>IoTA</p>
          <p>MySQL
Smartphone IDs and Device Capabilities</p>
          <p>Query
FOAF
{ The Registration service is used to register new devices into the system. It
provides methods for generating links between devices and the physical
entities they represent using the IoTa domain model. When user registers device
he/she is given unique ID, which should be used over the whole IoT system
to send generated or intended provenance data to our system. For example,
if the device is communicating with the server and server is acting upon the
data that was collected from IoT device, provenance of the transactions or
processes that were carried out externally should be captured and send to
our system.
{ The Update service provides methods for updating information about devices
in the system. This includes the ability to update the provenance of the
device and its use. On how to update provenance and other IoT device
information reader can refer to our guidelines. This service also provides a
method for associating smartphone IDs and devices when users accept (or
decline) the capabilities of the device via our app.
{ The Capability Reasoning and Filtering service is designed to reason about
the provenance information associated with devices in order to infer direct
or indirect capabilities. This service makes use of a rule-based reasoner
implemented using the TopBraid SPIN API4 to evaluate rules of the kind
described in Section 3.1. Since the smart devices, their services and third-party
smart application can generate vast amount of provenance metadata, it was
necessary to implement an e cient mechanism to lter redundant repeated
capabilities that are already being recorded. For example, public security
camera is capable of motion detection. For each motion event activation the
camera would generate provenance, which would be sent to our system. A
user may only wish to know that camera has motion capabilities.
{ The Query service is used for extracting information about an IoT device
based on the metadata stored in our system (including provenance and
capability inferences).
4 http://topbraid.org/spin/api/
{ The Noti cation service checks for changes in the capabilities of registered
devices every hour. If the service detects such changes push noti cation
messages are sent to the relevant users (using the smartphone IDs associated
with the device) informing them of the new capabilities.
2.4</p>
        </sec>
      </sec>
      <sec id="sec-2-4">
        <title>Smartphone app</title>
        <p>The services described above are accessible from our mobile app via a RESTful
API layer and JSON5 is used as the data interchange format. Devices in our API
are recognised by a custom URL http://t3domain/devices/fDeviceIDg where the
DeviceID represents the device identi er encoded in our Trusted Thing NFC tag.
Using the devices URL we can support di erent types of GET and POST actions
to retrieve or create information about devices. The app listens for NFC events
and intercepts the signal in order to determine if the device was registered with
our system. If so, it would retrieve characteristics and list of inferred capabilities
derived from past behavior of the device. The app also summarizes in pictorial
representation all the organizations associated with it and the type of data that
are being collected. If user is happy with the capabilities, he/she has the option
to either Accept or Decline the use of the smart device or service associated with
it. If accepted, user can store the device under his/hers own nickname so the
user can reference to it in the future. Once user accepted the device
capabilities, he/she also subscribes in our system to be noti ed about any changes in
capabilities (e.g. capability changes or new capability is detected).</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>The Trusted Tiny Things Semantic Framework</title>
      <p>In order to inform the design of a semantic framework for IoT devices we have
conducted three participatory design events involving a total of 14 participants
with di erent technological backgrounds. Participants were asked to discuss
issues surrounding the capabilities of IoT devices. Questions were posed such as:
What do you think are the capabilities of this device? and What kind of
capabilities would you want to be aware of before interacting with this kind of device?.
Guided by user requirements we have designed an ontological framework to
support inferences about device capabilities using provenance.</p>
      <p>In order to retrieve information about IoT devices (characteristics,
provenance, capabilities, etc.) it is necessary to be able to identify things (e.g. in
car black box,smart fridge) and their IoT components (tag, device, sensor or
service).</p>
      <p>
        Bandara et al. [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] presents a semantic model for describing IoT devices. While
this model is capable of describing device characteristics, it does represent
relationships between the devices, services and their usage in the context of smart
domains (e.g Smart Cities, IoT systems). Kortis et al. [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] describe an ontology
that represents knowledge about `Things' in the IoT domain and the way they
should interoperate. The authors have created a model describing IoT concepts
by introducing ontological de nitions such as Physical Entity, Control Entity,
Electronic Device, Smart Entity Cluster and Smart Network. While this
ontology is capable of capturing some relationships it is mostly focused on nding a
common framework to allow deployment of IoT devices into the existing Internet
infrastructure for service discovery and it is not suitable for our needs as it is
too focused on low level service description.
      </p>
      <p>
        The Internet of Things Architecture6(IoTa) is another project working
towards building a common architecture for the future Internet of Things. They
have developed a conceptual model [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] to describe the IoT domain based on
previous work from Serbanati et al. [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] and Haller [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]. The main aim of the IoTa
Domain model is to characterise the di erent entities in the IoT domain (e.g.
User, Service, Device, Physical Entity, Virtual Entity and Resource) see Figure
3.
      </p>
      <p>In order to reason about device capabilities we need to be able to represent
the provenance of an IoT device (e.g. processes, agents and the data being used
and generated). In our model we describe such provenance using the emerging
W3C PROV-O7 ontology as it is designed to be applicable to a wide range of
applications and domains. PROV-O de nes concepts such as: prov:Entity
(physical, digital, conceptual); prov:Activity (something that occurs over a period of
time and acts upon or with entities.); and prov:Agent (something that bears
some form of responsibility for an activity). Using this ontology it is possible
to describe who is the agent responsible for a speci c process (prov:Activity )
taking place (e.g. who collects my position location data) or what information</p>
      <sec id="sec-3-1">
        <title>6 http://www.iot-a.eu</title>
      </sec>
      <sec id="sec-3-2">
        <title>7 http://www.w3.org/TR/prov-o/</title>
        <p>iota:represents
iota:VirtualEntity ComIpooTnent
“BlackBox Controller</p>
        <p>Implementation”
iota:Sensor
“3G Transmitter”
iota:isAssociatedWith
iota:Sensor
“GPS Sensor”
iota:User
“Car Holder”
iota:interactsWith
iota:PhysicalEntity
“INSURANCE HOLDER</p>
        <p>CAR”
iota:isAttachedTo
iota:Device
“BlackBox”
iota:contains
are being created generated (e.g. device generated information about the speed).
We were able to align PROV-O with IoTa Domain Model so we can be more
descriptive about IoT devices. Moreover by combination of these two semantic
models we can better capture the creation,usage and ow of information in smart
infrastructures.</p>
        <p>Figure 4 shows an example of our framework being used to represent a in-car
black box device. With the provenance support provided by PROV-O we are able
to identify not only the high level concepts of IoT system, but speci c data and
relationships between them. In this case there is a process (prov:Activity ) which
used the GPS sensor to calculate current speed of vehicle and generated another
prov:Entity containing calculated information about driver's speed. These
information are then used by external process which calculates insurance premium.
Note that both black box controller and insurance smart service acted on behalf
of the same company. Participants during our design exercises highlighted the
need to provide contact information about agents (individuals or organisations)
responsible for certain devices and therefore we use the FOAF8 ontology. The
class foaf:Organization was de ned as a subclass of prov:Agent.
3.1</p>
        <sec id="sec-3-2-1">
          <title>T3 Model and Capability Inference Rules</title>
          <p>As discussed earlier in this paper, PROV-O allows us to answer some of the
issues related to transparency of IoT devices in smart environments, such as
who is responsible for a device, what data is generated and where such data
is transmitted. However, in PROV-O it is not possible to distinguish between
personal and non-personal data, neither it is possible to describe the purpose
behind the use of such data.</p>
          <p>We designed an ontology (T3 ontology) to support two important aspects of
the reasoning required to infer and detect device capabilities. Firstly,the ontology</p>
        </sec>
      </sec>
      <sec id="sec-3-3">
        <title>8 http://xmlns.com/foaf/spec/</title>
        <p>prov:actedOnBehalfOf
prov:SoftwareAgent</p>
        <p>iota:Service
“Insurance Company Smart</p>
        <p>Service”
iota:isAssociatedWith
prov:wasAssociatedWith
prov:wasGeneratedBy
prov:Entity
“New Premium”</p>
        <p>prov:Activity
“Calculate Insurance Premium”
prov:used
prov:Agent
“Insurance
Company”
prov:Entity
iota:Device
“BlackBox”
iota:contains
prov:Entity
iota:Sensor
“GPS Sensor”
prov:used</p>
        <p>prov:actedOnBehalfOf
iota:represents
prov:SoftwareAgent ComIpooTnent
iota:VirtualEntity
“BlackBox Controller</p>
        <p>Implementation”
prov:wasAssociatedWith
prov:Entity
“40 km/h”
prov:wasGeneratedBy</p>
        <p>prov:Activity
“Calculate Current Speed of Vehicle”
provides annotations over PROV-O concepts capturing the kind of information
identi ed by our participants. These annotations include:
{ The ttt:PersonalData class is used to identify if a prov:Entity represents
data that can be personal to individual. Human-readable text of the data
description can be attached to the prov:Entity via ttt:description property.
{ The ttt:purpose property is used to provide an human readable explanation of
why certain entities (described as personal data) are being generated or used.
This property is associated with prov:Activity (process,task) via prov:Usage
class.
{ The ttt:Capability class de nes di erent kinds of capabilities (e.g.
ttt:DataCollection, ttt:DataGeneration, ttt:DataSharing,ttt:DataGeneration) that can
be associated with iota:Devices. These associations (described by the
ttt:isCapableOf property) are made on the basis of a number of inference rules
described later in this section.
{ Properties such as ttt:securityDescription, ttt:deviceDesription, ttt:deviceName
were de ned to describe and further support transparency in human readable
format.</p>
        <p>Secondly, in order to infer the capabilities of IoT devices using our
ontological framework we can associate rules to speci c classes of ttt:Capability. We
make use of the SPIN ontology9 to support the use of SPARQL to specify rules
and logical constraints necessary to reason about capabilities. The rule is
designed to traverse a PROV-O provenance graph starting from an instance of
an iota:Device. To date, we implemented ve inference rules, which are closely
related to personal information: check if any IoT device or service is capable
of generating automatic bills for a user, check if there are personal data being
collected, rule to see if personal data are being used and why, detect if personal</p>
      </sec>
      <sec id="sec-3-4">
        <title>9 http://spinrdf.org/spin.html</title>
        <p>data are shared with third-party organisations, and detect what data is the
device or service generating. Implementation of some of these rules can be seen in
Figure 5.</p>
        <p>If any of the rule activates, it constructs new inferred facts about the device
in questions and forms them into capabilities (subclasses of ttt:Capability ). If
certain capability is already attached to the device (e.g. PersonalDataSharing)
ltering service (see Section 2.3) makes sure it won't recreate the same one,
unless there is new purpose or actor (e.g. there is a new agent the personal data
are being shared with). In this case the same type of capability is attached to
the device, but with changed properties.</p>
        <p>If data are uniquely identi ed and the provenance of the devices and services
associated with it is being captured and sent to our framework, system can
track down how far certain information (e.g. personal data) ows in the whole
IoT system or smart infrastructure. This will allow to identify all the agents,
purpose and processes, that played any part in creation, generation, modi cation
and aggregation of personally identi able data.</p>
        <p>We have also implemented rules that are used to determine what kind of
provenance has been used to infer a speci c device capability and if the
capabilities are direct(on the device) or indirect(capability of external entities). However,
this is out of the scope of this demo paper.
4</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>Demonstration Content</title>
      <p>We organise this demo in two parts. The rst part demonstrates how our
mobile app can be used to query and visualise provenance information about IoT
devices in the bus stop scenario. The second part of our demonstration explores
a scenario, in which provenance is generated and sent to our system in real-time
from IoT devices. We demonstrate how a user is noti ed about changes when
the capabilities of an associated device change.
4.1</p>
      <sec id="sec-4-1">
        <title>Bus Stops in Aberdeenshire</title>
        <p>Near Field Communication (NFC) tags are being deployed on the bus stops in
Aberdeenshire, Scotland UK so that user can retrieve real-time timetable
information. These passive IoT devices embed a URL that is used to redirect and
NFC-enabled smartphone to a service providing timetable information for a
speci c city location. Users may think that this service is provided by Aberdeenshire
Council, but instead it delegates to third-party organisation (RSL Ltd).
Moreover, both organisations are collecting certain kinds of personal data (e.g. IP
Address, smartphone model and OS, and the version of the web browser users).
Users deserve to know what data they are providing and to whom and they
should also have an option to refuse to use the service. To this end, the Trusted
Tiny Things tags and system have been deployed to more than 2300 bus stops
in Aberdeenshire in 2014.</p>
        <p>Demonstration content:
{ For the purpose of this demonstration we built a replica bus stop. The NFC
tag attached to the bus stop will be scanned using an NFC-enabled
smartphone.
{ We explain how the system checks if the device was previously accepted buy
the owner of the smartphone. We demonstrate how the meta-data associated
with the IoT device (bus-stop tag) and the meta-data associated with the
timetable services is used in order to infer capabilities.
{ Using the mobile app, we show what companies are associated with the
device, who is the owner, manufacturer and list of capabilities, which will be
explorable by clicking on them to nd out further details about them. We
will also demonstrate how the capability of the device can be accepted and
recorded into the system.
{ Finally, we will demonstrate how the system can be used for devices that
have already been accepted where the app will show non intrusive dialog
for few seconds informing the user about the time and date he trusted the
device and how the user is immediately redirected to the service.</p>
        <p>For a video presentation of this case study, please visit our website10.
4.2</p>
      </sec>
      <sec id="sec-4-2">
        <title>In-car Black box</title>
        <p>The second part of the demonstration shows how our system can make use
of real-time provenance data being generated by IoT devices. We simulate an
insurance company that is installing tracker devices (black boxes) into their
customer's vehicles so they can use the data collected to tailor the insurance
premiums based on real driving behaviour. For this case study, we developed a
replica black box and associated IoT services (insurance company service and a
car manufacturer service) which can communicate and exchange information in
a IoT ecosystem.
10 http://t3.abdn.ac.uk</p>
        <p>This scenario will be demonstrated in two stages:</p>
        <p>In the rst stage of this demonstration we will deploy a replica black box
device to detect the location of a vehicle and the speed the vehicle is travelling.
We will demonstrate how the insurance provider uses the information generated
by the device to understand the driving patterns, current location and speed for
premium calculation.</p>
        <p>Using the Trusted Tiny Things mobile app we will scan the tag attached
to the black box and visualise an initial set of capabilities. Such capabilities are
de ned based on the ow of data between the device and the supporting services.
The ow of data can be seen in Figure 6.</p>
        <p>In the second stage of this demonstration we will introduce new actor (car
manufacturer service ) to the IoT ecosystem. Previously, the insurance company
was calculating premiums based on the information collected from the black box.
In this scenario, the insurance company will begin to share accelerometer data
with the car manufacturer's service in order to determine out how the policy
holder's services their car.</p>
        <p>We will illustrate how the new capabilities of the service are determined
when the new service is activated. In this example, we will illustrate how the
policy holder will be noti ed that personal data were shared with a third-party
company. The ow of data associated with this scenario is illustrated in in Figure
7.</p>
        <p>Black Box</p>
        <p>Braking and
Acceleration Data</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>Acknowledgements</title>
      <p>This research is supported by the Research Council UK Digital Economy IT as
a Utility Network+ (EP/K003569/1) and the dot.rural Digital Economy Hub
(EP/G066051/1).</p>
    </sec>
  </body>
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