A Deontic Logic Model of Attribute-Based Information Flows in
Database-Defined Networks with Application to Healthcare Monitoring
Benjamin Aziz
a
, Ukamaka Oragwu
b
and Safa Tharib
c
School of Creative and Digital Industries, Buckinghamshire New University, High Wycombe, U.K.
Keywords:
Attribute-Based Policies, DDNs, Deontic Logic, Information Flows, SDNs.
Abstract:
This paper addresses the increasing demand for robustness and reliability in modern software-defined net-
works, particularly in the context of critical business applications such as the healthcare domain. Traditional
network architectures are vulnerable to both unintentional and intentional failures, leading to significant finan-
cial losses, especially in the healthcare sector. The paper propose a formal model for attribute-based informa-
tion flow control in database-defined networks, which leverages attributes to evaluate compliance with desired
network conditions, such as the quality of connectivity. Additionally, the paper employs deontic logic to define
permissible, prohibited and obligatory changes to network configuration tables. The paper demonstrate how
this model can enhance the management of body-area networks and ensure quality of service in healthcare
monitoring. The findings suggest a promising direction for improving network reliability and security.
1 INTRODUCTION
The rapidly increasing number of critical business
applications and high-volume data transmission over
modern day communication networks brings up the
demand for a high degree of robustness and reliabil-
ity. Communication networks are prone to both unin-
tentional (or unplanned) failures, e.g. human errors,
natural disasters, overload and software bugs etc., as
well as to intentional (or planned) failures caused by
the process of maintenance or malicious interference
(Markopoulou et al., 2004). All network elements
(e.g. forwarding devices and links) are susceptible to
failure incidents and leading to network facilities (like
routers) being harmed. In addition, failures cause fi-
nancial losses to service providers, e.g. cloud ser-
vice providers. According to the statistics of 28 cloud
providers from 2007 to 2013 (C
´
erin et al., 2013), fi-
nancial losses were estimated at approximately $285
million as a consequence of infrastructure and appli-
cation failures. As networks evolve to address these
challenges, Software-Defined Networking (SDN) has
emerged as a promising solution to overcome the
rigidity of traditional architectures, but it also intro-
duces new security concerns that need to be addressed
a
https://orcid.org/0000-0001-5089-2025
b
https://orcid.org/0009-0008-5213-9967
c
https://orcid.org/0000-0002-0088-3363
(Maleh et al., 2023), for example in relation to denial
of service attacks (Sivarajan and Jeyalakshmi, 2024).
The success of OpenFlow (McKeown et al., 2008)
in recent years as an SDN platform, brought much
attention from both the academic and business com-
munities and has driven the development of SDN re-
search as a next generation of networking system ar-
chitectures. More recently however, a new approach
to the implementation of SDNs has emerged that aims
to simplify the task of network administration through
the introduction of further data-based abstractions of
the control and data planes. This approach is called
Database-Defined Networking (DDN) (Wang et al.,
2016), in which the entire network is represented us-
ing a standard relational database. The communica-
tion network is abstracted as a database that can be
managed like any other database. Such management
is performed through a standard interface, like SQL,
where the network state can be queried and its config-
uration updated using standard database languages.
With this approach, it becomes straightforward, for
example, to divide the network into multiple zones
and enforce access control rules on those zones using
access control lists as was demonstrated in (Glaeser
and Wang, 2016).
In SDNs in general, network-wide policies and
invariants are defined in high-level terms that are
translated to device configuration. Eventually, the
actual behavior of the network may violate policies
330
Aziz, B., Oragwu, U. and Tharib, S.
A Deontic Logic Model of Attribute-Based Information Flows in Database-Defined Networks with Application to Healthcare Monitoring.
DOI: 10.5220/0013144900003899
Paper published under CC license (CC BY-NC-ND 4.0)
In Proceedings of the 11th International Conference on Information Systems Security and Privacy (ICISSP 2025) - Volume 2, pages 330-341
ISBN: 978-989-758-735-1; ISSN: 2184-4356
Proceedings Copyright © 2025 by SCITEPRESS – Science and Technology Publications, Lda.
(e.g., routing policies, security policies) and invari-
ants (e.g., connectivity) due to some untested appli-
cation bug, a network controller mistranslation, or a
faulty protocol implementation in network devices.
Therefore, network correctness must be constantly
monitored in order to detect possible violations. Such
problems may be encountered when network con-
trollers are shared by different users or applications,
or multiple controllers operate in the same domain,
leading to conflicting rules, violation of policy, or net-
work faults, such as loops, black holes, access control
violations, etc. Malicious parties may even bypass
security policies by defining strategic flow rules to re-
label and redirect traffic.
In this paper, we outline a model of attribute-based
information flow control for DDNs, which attempts to
address the clarity of DDN (and generally, SDN) net-
work policies and address the above problems. Ev-
ery DDN has a configuration table that defines how
packets are to be routed from their initial source to
the final destination. We assume that nodes, compos-
ing such configuration tables, have attributes, which
can be used to determine whether a configuration ta-
ble satisfies certain desirable conditions or not. Ad-
ditionally, we outline a model based on deontic logic
(Von Wright, 1951) to determine whether changes to
the configuration table are permissible, prohibited or
obligatory. As far as we know, no previous works
have addressed the problem of specifying SDN poli-
cies using this specific approach.
The rest of the paper is organised as follows. In
Section 2, we discuss state-of-the-art literature related
to the areas covered in this paper. In Section 3, we
provide some background on DDNs and outline the
theoretical model underlying DDNs, which we use
in this paper. In Section 4, we define our model
for attribute-based information flows in DDNs, and
in Section 5 we consolidate this model using deon-
tic logic operators to be able to express permission,
prohibition and obligation policies. In Section 6, we
demonstrate how this model can be applied to a case
study involving body-area networks, and show how
the configuration of such networks can benefit from
our deontic logic-based information flow policies. In
Section 7, we show how deontic policies, in particular
obligation policies, can be used to implement qual-
ity of connectivity subscription levels in a healthcare
monitoring environment. Finally, in Section 8, we
conclude the paper and discuss future research.
2 RELATED WORK
We review in this section some state-of-the-art works
in literature, which are of relevance to our work pre-
sented in this paper, along four main strands: The
use of deontic logic for the specification of security
policies, non-policy-based security mechanisms for
SDNs, security policy frameworks for SDNs with ap-
plication to other (non-healthcare) domains and secur-
ing healthcare networks.
Deontic Logic for Security Policy Specifications.
The use of deontic logic for security policy specifi-
cations is a concept that has been explored for many
years. For example, Ortalo (Ortalo, 1996) looked into
this particular problem by addressing the difficulties
of ensuring consistent adherence to security policies.
Their work demonstrated how deontic logic, which
formalises permissions, obligations and prohibitions
can help overcome these challenges. Ortalo also in-
troduced a graphical method to represent these poli-
cies, making it easier to visualize and manage com-
plex security rules. Similarly, in 2012, Amini et al.
(Amini et al., 2012) applied a variant of deontic logic,
called MASL (Multi-Authority Security policy Lan-
guage), to specify and enforce security policies within
Multi-Security Domain (MSD) environments. Their
approach facilitated the coordination and administra-
tion of security policies across multiple domains, en-
suring consistency and compliance, even in the face
of differing administrative boundaries. In (Cheng and
Miura, 2006), Cheng and Miura introduced the use
of deontic relevant logic as a foundational framework
for reasoning about information security and assur-
ance, allowing for precise specification of security
policies, enabling systems to enforce rules and de-
tect violations more effectively. More recently, Deb
et al. (Deb et al., 2024) explored declarative logic-
based decision-making, which can complement deon-
tic logic in optimising agent-based security decisions
by formalising conditions under which actions are
obligatory or prohibited. Olszewski et al. (Olszewski
et al., 2024), on the other hand, explore the applica-
tion of deontic logic by attributing specific character-
istics, or “attributes” to network nodes, which then
makes it possible to assess whether configurations
comply with certain desired conditions. Their use of
deontic logic offers a formal framework to determine
if changes to network configurations are permissible,
prohibited or obligatory, which is especially valuable
in preventing policy violations, routing errors, or ac-
cess control breaches. This approach enhances secu-
rity compliance and fault tolerance. Aside from the
above, Olivieri et al. (Olivieri et al., 2024) introduce
A Deontic Logic Model of Attribute-Based Information Flows in Database-Defined Networks with Application to Healthcare Monitoring
331
the concept of deontic meta-rules, which provide a
higher-order structure for interpreting and resolving
conflicts between network policies. This is partic-
ularly relevant in environments where multiple con-
trollers or users interact with the same network infras-
tructure, as meta-rules help prioritise and harmonise
potentially conflicting flow rules. Finally, Makin
(Makin, 2024) further explores the foundational as-
pects of deontic operators, emphasising their appli-
cability in formalising ethical and procedural rules
within complex systems.
Non-Policy-Based Security Mechanisms for SDNs.
Beyond deontic logic and security policy-based
frameworks, other mechanisms have also been pro-
posed to secure SDNs. For example, Chaudhary et
al. (Chaudhary et al., 2018) developed an SDN-
enabled, multi-attribute secure communication model
for Industrial Internet of Things (IIoT) environments,
particularly smart grids. Their model combines
a cuckoo-filter-based (Fan et al., 2014) forward-
ing scheme, attribute-based encryption (Goyal et al.,
2006) and a Kerberos-based (Steiner et al., 1988) au-
thentication system, enhancing both security and net-
work efficiency. Vyas and Shyamasundar (Vyas and
Shyamasundar, 2021) introduced SecSDN, a new ar-
chitecture that addresses SDN vulnerabilities stem-
ming from weak authentication between controllers
and switches. SecSDN uses repetitive hashing to ver-
ify flow tables and detect malicious switches, offering
enhanced security without imposing overhead on net-
work performance. Shi et al. (Shi et al., 2017) pro-
posed an enhanced SDN security framework target-
ing threats at multiple layers—application, control,
resource and interface. Their architecture emphasises
attribute-based encryption to strengthen access con-
trol and defend against known vulnerabilities. While
SDN’s popularity continues to rise, the authors high-
light that security research in this areas remains in its
infancy. Smith et al. (Smith et al., 2016) presented
an information-theoretic approach to partitioning net-
works, incorporating node and link attributes. Their
method improves on existing algorithms by identify-
ing network modules that reflect real-world commu-
nity structures, though further research is needed to
address highly correlated attributes. Finally, smart
contracts and the blockchain technology have also
been suggested as a possible approach for securing
the SDN. The authors in (Sivarajan and Jeyalakshmi,
2024) address this by proposing an attribute-based ac-
cess control mechanism using blockchain smart con-
tracts to prevent unauthorised traffic and mitigate de-
nial of service risks in SDNs. This approach enhances
security by ensuring only authorised traffic reaches
the control plane.
Security Policies for SDNs in Other Domains. Se-
curity policies have also been employed to enhance
SDN security and reliability properties within do-
mains of application other than the healthcare do-
main. For example, Zhu et al. (Zhu et al., 2020)
introduced Attribute-Guard, an attribute-based flow
authentication and fine-grained access control frame-
work for SDNs. This framework addresses security
gaps by verifying the legitimacy of data flows through
an attribute-based authentication protocol, effectively
rejecting malicious flows without impacting network
performance. Another relevant work to ours is that
of Al-Haj and Aziz (Al-Haj and Aziz, 2019) intro-
duced a method for enforcing multilevel security poli-
cies in DDNs using Row-Level Security (RLS) in re-
lational database systems. Their approach provides
fine-grained control over data flow by applying up-
ward and downward information flow policies at the
individual table row level, simplifying network man-
agement while enhancing security. This mapping
from high-level security policies onto low-level rules
also suggests a method for the refinement of security
policies in the context of SDNs/DDNs. The authors
in (Varadharajan et al., 2019) explored a policy-based
architecture addressing inter-domain security essen-
tial for environments like healthcare, finance and criti-
cal infrastructure, where information can flow accross
multiple domains. Finally, (Karmakar et al., 2020)
proposed a dynamic policy-enhanced SDN architec-
ture, with the ability to adjust policies in real-time, in
domains such as Cloud computing.
Securing Healthcare Networks. The last literature
group we consider here are works relevant to the
securing of healthcare networks. We use the term
“healthcare networks” to refer to any network tech-
nology (including SDNs) used to carry health-related
information, where sensitive patient data and criti-
cal medical systems are interconnected. We men-
tion here only a few such relevant examples. Es-
teves and Rodr
´
ıguez-Doncel (Esteves and Rodr
´
ıguez-
Doncel, 2024) explore ontologies and policy lan-
guages within the GDPR framework (European Par-
liament and Council of the European Union, 2016),
which is highly relevant in healthcare, where stringent
data privacy regulations must be adhered to. Their
work emphasises the need for well-defined policies
to govern how sensitive data are to be handled and
shared across healthcare networks. This work repre-
sents a high-level approach to ours, nonetheless, of in-
terest as future approach. On the other hand, taking a
low-level perspective, Walid et al. (Walid et al., 2024)
ICISSP 2025 - 11th International Conference on Information Systems Security and Privacy
332
compare various attribute-based encryption schemes
that secure healthcare systems by controlling access
to sensitive data. Their work underscores the impor-
tance of “attribute-based approaches” in safeguarding
patient information, enabling only authorised users to
access critical data based on defined attributes. Zhang
et al. (Zhang et al., 2024) further enhance this ap-
proach with a secure attribute-based dynamic data
sharing scheme specifically designed for the Internet
of Medical Things, which not only hides access poli-
cies but also efficiently updates them. Both of these
two works represent a future direction for our work in
refining our approach to the actual system level.
3 A MODEL OF DDNS
In the model of DDNs adopted in (Alhaj and Aziz,
2019), it is possible to define a configurable network
in terms of three tables of data: First, a network topol-
ogy table, which defines how nodes are physically
connected, second, a configuration table, which de-
fines flows through the network that packets can be
routed through and finally, a table that defines flow
reachability attributes. For the purpose of this paper,
we only need to focus on configuration tables.
Definition 1 (Configuration Table).
Define a DDN configuration table as the following
function (Alhaj and Aziz, 2019):
cf : N ((N × N × N) N)
The assumption here is that all nodes and flows
are identified as numbers. cf takes as input a flow’s
number, f
id
N, and returns as output a partial injec-
tive function. This function provides a sequence of
triples representing the identity numbers of the nodes
forming the flow path. These nodes are defined as
the number of the current node (switch), s
id
N, the
previous node, p
id
N, and the next node, n
id
N.
Each triple is an expression of the configuration of
the various switches on the network that the flow path
traverses. The fact that each triple is itself mapped
to a number renders the triples as a finite sequence
(or a tuple). We call the set of all configuration ta-
bles C. In order to simplify the model later, we also
refer to each flow element of a configuration table cf
as flow
i
, where cf = {flow
1
,...,flow
n
}, i {1,..., n}
and n =| cf |. Sometimes we drop index i and use flow
to refer to any flow in cf.
The general form of an n-flow configuration table
looks like the following:
cf =
( f
1
, {((p
11
,s
11
,n
11
),1),
.
.
.
((p
1k
f
1
,s
1k
f
1
,n
1k
f
1
),k
f
1
)}),
.
.
.
( f
n
, {((p
n1
,s
n1
,n
n1
),1),
.
.
.
((p
nk
f
n
,s
nk
f
n
,n
nk
f
n
),k
f
n
)})
We use the notation flow
i
. j to refer to the specific
j
th
{1,...,k
f
i
} entry in the table for flow
i
. For ex-
ample, flow
1
.1 refers to the entry that is (p
11
,s
11
,n
11
)
in cf above.
Consider further the following example of a con-
figuration table mentioned in (RAVEL, 2024):
fid pid sid nid
------ ------- ------ ------
1 5 1 3
1 1 3 4
1 3 4 6
We simply model this as:
{(1,{((5,1,3),1),((1,3,4), 2), ((3, 4, 6),3)})}
where flow
1
.1 = (5,1,3), flow
1
.2 = (1,3,4) and
flow
1
.3 = (3,4,6).
Naturally, a DDN, as a variation of a software-
defined network, should be capable of changing its
flow configurations. We model this change in terms
of the following relation:
: C C
Formally, is defined by the rules of Figure 1.
Rule (R1) adds a flow, that currently does not ex-
ist, to a configuration table. Rule (R2) removes a flow
from a configuration table. Rule (R3) replaces a pre-
vious node in an entry in a flow in some configura-
tion table with a new previous node, such that the new
node is different from the replaced one. Every other
entry in the flow remains intact. Rule (R4) replaces
the current node in an entry in a flow in some config-
uration table with a new current node, such that the
new node is different from the replaced one. Every
other entry in the flow remains intact. Finally, rule
(R5) replaces the next node in an entry in a flow in
some configuration table with a new next node, such
that the new node is different from the replaced one.
Every other entry in the flow remains intact.
The relation only expresses what changes are
possible starting from some configuration table, and
not that such changes actually will take place. In other
A Deontic Logic Model of Attribute-Based Information Flows in Database-Defined Networks with Application to Healthcare Monitoring
333
(R1) cf (cf flow), where flow / cf
(R2) cf (cf\{flow}), where flow cf
(R3) cf (cf\{flow}) flow
, where flow cf and
flow. j = (p
id
,s
id
,n
id
) flow
. j = (p
id
,s
id
,n
id
) p
id
̸= p
id
i ̸= j : flow
.i = flow.i
(R4) cf[flow] cf[flow
], where flow cf and
flow. j = (p
id
,s
id
,n
id
) flow
. j = (p
id
,s
id
,n
id
) s
id
̸= s
id
i ̸= j : flow
.i = flow.i
(R5) cf[flow] cf[flow
], where flow cf and
flow. j = (p
id
,s
id
,n
id
) flow
. j = (p
id
,s
id
,n
id
) n
id
̸= n
id
i ̸= j : flow
.i = flow.i
Figure 1: Rules of the relation.
words, it expresses change semantics, and not a tran-
sitional one (Van Benthem and Bergstra, 1994).
The above rules model every fundamental change
required on the configuration table. We ignore cos-
metic changes such as the changing of the flow id,
f
id
, or the range of indices (e.g. j variables in Figure
1) used to order entries for each flow, as such changes
would result in congruent tables. We also write
to
denote the reflexive transitive closure of . In other
words, cf in cf
cf
can arrive at cf
in zero or more
finite number of steps.
4 ATTRIBUTE-BASED
INFORMATION FLOWS
Attribute-based information flow policies (Yuan and
Tong, 2005) are a framework for managing the flow
of sensitive information in computing systems based
on a set of defined attributes. Unlike traditional ac-
cess control models that grant or deny access based
solely on roles or identities, attribute-based policies
consider a wider range of attributes such as user cre-
dentials, contextual data, time of access and the sen-
sitivity levels of the data themselves. This allows for
more fine-grained and dynamic control over how in-
formation is shared, processed and restricted.
In our case, we start by first defining for each
node (switch or host) in the network, e N, its set
of attributes drawn from A, the set of all possible
attributes, using the following function:
attr : N (A)
such that, attr(e) = {a
1
,...,a
n
}. We assume that each
node has at least one attribute as a minimum, e.g. its
human-readable name or its IP address. In (Alhaj and
Aziz, 2019), the authors considered another example
of such attributes relevant to multi-level security
policies (Bell and LaPadula, 1973), namely security
levels, which could be drawn from a lattice structure
(Dilworth, 1950). Attributes can be resolved to their
values using the function:
attrValue : A Z
where we assume for simplicity that all our attributes
have values that are drawn from the set of integer
numbers. If not, then it is easy to imagine that there
is a mapping from the integer value to another value
of different type. Perhaps the most interesting aspect
of attribute values is that they are mutable; they
can change values in a dynamic system. Therefore,
we assume the presence of a change function,
: (A Z) (A Z), defined as follows:
attrValue[x 7→ y] attrValue[x 7→ y
]
We consider that a node’s attribute is a more funda-
mental concept than a link’s attribute, as the latter
may be expressed in terms of the attributes of its two
linked nodes. For example, to express that a link is
either up or down, we can define this as a predicate,
LinkUp:
LinkUp : A × A B
which takes as parameters two attributes representing
a node’s point of view of the link’s availability
with another node and returns a Boolean expressing
whether the link between the two nodes is up or down:
LinkUp(connection2e2,connection2e1) =
T, if attrValue(connection2e2) =
attrValue(connection2e1) = 1
F, otherwise
The connection2eX attribute has a value 1 if the
connection to node X is up and running from the
point of view of a node e, and 0 otherwise. In our
case, connection2e2 attr(e1) and connection2e1
attr(e2).
In general, we observe that for any two adjacent
nodes in a flow, it may be possible to state some-
thing about how their corresponding attributes re-
late. Hence, for any two nodes, e
1
and e
2
, there may
be some predicate, P({a
e1
1
,...,a
e1
n
},{a
e2
1
,...,a
e2
m
}),
defined over some of their attributes, whereby
ICISSP 2025 - 11th International Conference on Information Systems Security and Privacy
334
{a
e1
1
,...,a
e1
n
} attr(e
1
) and {a
e2
1
,...,a
e2
m
} attr(e
2
).
We call the set of all predicates on attributes of e
1
and
e
2
that we are interested in, Q (e
1
,e
2
), and we range
these over by variables P,Q etc.
We define now an information flow condition as
the following logical formula:
C :(Q (p
id
,s
id
)) ×(Q (s
id
,n
id
)) B
which takes any number of predicates defined on
attributes of adjacent nodes in a configuration table
flow j
th
entry, (p
id
,s
id
,n
id
) flow. j, and returns a
Boolean to signify whether the condition is True
or False. Note that this condition is general in that
it describes logically how the sets of predicates on
attributes of all adjacent nodes should be logically
related. For example, using the LinkUp predicate, we
could define the condition, EntryUp, as the conjunc-
tion of the status of consecutive links in a flow’s entry:
EntryUp =
LinkUp(connectionpid2sid,connectionsid2pid)
LinkUp(connectionsid2nid,connectionnid2sid)
therefore testing whether the two links in a
configuration table flow’s entry are up and
running. As expected, connectionpid2sid
attr(p
id
), connectionnid2sid attr(n
id
) and
connectionsid2pid,connectionsid2nid attr(s
id
).
On the other hand, the predicate:
LinkAnalysis(e2 analysis,e1 analysis) =
T, if attrValue(e2 analysis) = 1
attrValue(e1 analysis) = 1
F, otherwise
tests for whether either node in a link deploys some
packet analysis algorithm. We can now define the
condition:
PacketAnalysed =
LinkAnalysis(pid analysis,sid analysis)
LinkAnalysis(sid analysis,nid analysis)
which ensures that a packet is analysed at least once
in each flow’s entry.
From this, we say that a particular flow’s j
th
entry in a configuration table, flow. j, where flow cf,
satisfies a condition C, and write:
C flow. j, if and only if:
C({P
1
(attr(p
id
),attr(s
id
)),...,
P
k
(attr(p
id
),attr(s
id
))}, {Q
1
(attr(s
id
),attr(n
id
)),...,
Q
k
(attr(s
id
),attr(n
id
))}) = T
where flow. j = (p
id
,s
id
,n
id
). We use the variables
P
i
to range over predicates applying to previous and
current nodes, and Q
i
for predicates applying to
current and next nodes. Conversely, we say that the
condition is not satisfied, and we write:
C flow. j, if and only if:
C({P
1
(attr(p
id
),attr(s
id
)),...,
P
k
(attr(p
id
),attr(s
id
))},{Q
1
(attr(s
id
),attr(n
id
)),...,
Q
k
(attr(s
id
),attr(n
id
))}) = F
Definition 2 (Attribute-based Information Flow
Policies).
Define an attribute-based information flow policy
simply as a set of k-number of information flow
conditions:
θ = {C
1
,...,C
k
}
We call the set of all policies, Θ :
((Q (p
id
,s
id
)) × (Q (s
id
,n
id
)) B). Set-
ting up any policy for the network must satisfy the
following feasibility property.
Property 1 (Policy Feasibility).
Defining an attribute-based information flow policy,
θ Θ, must satisfy the following feasibility condition:
cf C ,C θ, flow cf, j dom(cf(flow)
1
) : C
flow. j
We next use the definition of attribute-based infor-
mation flow policies in conjunction with deontic logic
operators to state the conditions under which changes
in network configurations are permitted, prohibited
and obligated.
5 DEONTIC LOGIC OPERATORS
In this section, we suggest the use of deontic
logic operators as first formalised by von Wright in
(Von Wright, 1951) to ensure that configuration ta-
bles are changed in a correct manner. These opera-
tors are permissions (P ), prohibitions (F ) and obliga-
tions (O). They reflect situations where changes are
permitted, prohibited or obligated, respectively, when
applied to .
We now define the relation to denote the fact
that a deontic logic operator, op {P , F ,O}, holds
under a specific policy θ when applied to :
θ op(cf cf
)
A Deontic Logic Model of Attribute-Based Information Flows in Database-Defined Networks with Application to Healthcare Monitoring
335
For example, the relation θ F (cf
1
cf
2
) is True,
meaning it prohibits changing the configuration table
from its state cf
1
to state cf
2
under the θ policy. We
now expand on the definition of the relation for each
of the deontic logic operators, to include the ability to
express the logical conditions under which such oper-
ators apply.
5.1 Permissions
We start first by expressing what changes are permit-
ted under the presence of a policy θ. We write such
permission as follows:
θ P (cf cf
) such that C θ : C cf
Note here that the change is not necessarily triggered
by changes in node attributes in the original cf, rather
this could be any reason why cf requires changing.
The permission expresses purely authorised condi-
tions under which such changes may be applied to
network configurations.
5.2 Prohibitions
Prohibitions express policies that are the opposite
of permitted policies in which case they define the
conditions prohibited for configuration tables to be
changed to. This is defined as follows:
θ F (cf cf
) such that C θ : C cf
The following two-way implication holds natu-
rally (a change is not permitted if prohibited explicitly
and vice versa):
θ F (cf cf
) ¬ (θ P (cf cf
))
However, the following implication also holds
naturally (a change is not prohibted if permitted
explicitly):
θ P (cf cf
) ¬ (θ F (cf cf
))
but not vice versa. Nonetheless, a less secure vari-
ation might allow the opposite implication to also
hold (i.e. that a change is implicitly permitted if not
explicitly prohibited):
¬ (θ F (cf cf
)) θ P (cf cf
)
5.3 Obligations
Obligation policies state that once an entry in a con-
figuration table violates a policy condition, that entry
must be changed to one that satisfies the violated
condition. Such change is necessary and obligatory,
to maintain adherence to whatever good properties
are sought of the network. More formally:
θ O(cf cf
) such that C θ : C cf
Note that, in this most primitive form of an obligation
policy, we do not require that C θ : C cf
. This
is because an obligation policy states that the change
must take place, but not necessarily to a good con-
figuration. If we want such good configuration, then
we must keep on trying until we reach it, or we must
prohibit transitioning to a bad configuration.
The following implication holds naturally (an
obligated change needs to be permitted explicitly):
θ O(cf cf
) θ P (cf cf
)
Obviously, the opposite implication is not true.
6 EXAMPLE: RECONFIGURING
A BODY AREA NETWORK
The case study we adopt in this paper focuses on Body
Area Networks (BANs) as an example of healthcare
monitoring systems. A BAN (Movassaghi et al.,
2014) is a wireless network of wearable or im-
plantable devices that monitor and transmit physio-
logical data from a person’s body, typically for health-
related purposes. These devices, such as sensors, ac-
tuators and communication modules, interact to track
vital signs like heart rate, blood pressure or glu-
cose levels in real time enabling personalised health-
care and remote monitoring by medical profession-
als. BANs often use short-range wireless communi-
cation protocols like Bluetooth or ZigBee to ensure
secure, low-power transmission of data within the hu-
man body’s vicinity. However, some of the more ad-
vanced recent BAN devices also use mobile networks
(3G/4G/5G) and WiFi.
A BAN could consist of the following elements:
A low functionality health monitoring watch de-
vice (e.g. health smart watch, glucose monitoring
device etc.). This is called D1
A high functionality health monitoring device
(e.g. home ECG monitor). This is called D2
ICISSP 2025 - 11th International Conference on Information Systems Security and Privacy
336
A device configuration app called APP, which is
used to configure the settings of D1 and D2
A back-end server called SRV, which is used to
collect data from D1 and D2 and analyse them
Figure 2 illustrates an example of a BAN, with the ex-
ample elements mentioned above, as well as the var-
ious connectivity modes (5G, 4G, 3G, WiFi). We as-
Figure 2: An Example of a BAN with connectivity modes
to a server and an app.
sume that D1 can only be reached via 3G and WiFi
connectivity, whereas D1 can be reached via 4G, 5G
and WiFi connectivity. The APP runs on a standard
smart phone, with 4G and WiFi connectivity, and fi-
nally, the back-end server is reachable via any type of
connection (3G, 4G, 5G and WiFi).
The network in Figure 2 is defined through the fol-
lowing instance of a DDN configuration table, which
we call cf
ban
:
fid pid sid nid
------ ------- ------ ------
1 -- APP CWiFi
1 APP CWiFi D2
1 CWiFi D2 --
2 -- D2 CWiFi
2 D2 CWiFi SRV
2 CWiFi SRV --
3 -- D2 C3G
3 D2 C3G SRV
3 C3G SRV --
4 -- APP CWiFi
4 APP CWiFi D1
4 CWiFi D1 --
5 -- APP C4G
5 APP C4G D1
5 C4G D1 --
6 -- D1 CWiFi
6 D1 CWiFi SRV
6 CWiFi SRV --
7 -- D1 C4G
7 D1 C4G SRV
7 C4G SRV --
8 -- D1 C5G
8 D1 C5G SRV
8 C5G SRV --
One of the requirements in such networks as stated
in (Gama et al., 2007), for example, is that the body
area network must continue to function and operate
during reconfiguration (including network topology
reconfiguration), and a second requirement is that the
reconfiguration must not fail (i.e. it should result in
a functioning new system). Here, we focus more
on the idea a reconfiguration must result in a sound
(i.e. functional or exhibiting desirable non-functional
properties) network topology.
In the following, we discuss examples of permit-
ted, prohibited and obliged deontic-based policies.
6.1 Permitted Policies
As an example of permitted policies, let’s consider
the following policy:
θ P (cf
ban
cf
smallban
)
whereby θ is defined by the following soundness
conditions:
C1 : flow cf
smallban
: flow.2 = (p, s, n)
(first is device D1(p,s) second is server(s,n))
C2 : flow cf
smallban
: flow.2 = (p, s, n)
(first
is device D2(p, s) second is server(s,n))
C3 : flow cf
smallban
: flow.2 = (p, s, n)
(second is device D1(s, n) first is app(p,s))
C4 : flow cf
smallban
: flow.2 = (p, s, n)
(second is device D2(s, n) first is app(p,s))
These conditions essentially ensure that both devices
D1 and D2 are connected (through some means) to
both the back-end server and the configuration app.
We call these conditions informally the soundness
conditions, as they ensure that the BAN has the cor-
rect and necessary connectivity among all its compo-
nents. The check in each condition is applied to the
second entry for each flow in the configuration table.
The definition of the operators in the above
conditions is given as follows:
first is device D1(p,s) =
T, if attrValue(identity.p) {D1}
F, otherwise
A Deontic Logic Model of Attribute-Based Information Flows in Database-Defined Networks with Application to Healthcare Monitoring
337
first is device D2(p,s) =
T, if attrValue(identity.p) {D2}
F, otherwise
second is device D1(s, n) =
T, if attrValue(identity.n) {D1}
F, otherwise
second is device D2(s, n) =
T, if attrValue(identity.n) {D2}
F, otherwise
second is server(s,n) =
T, if attrValue(identity.n) {SRV }
F, otherwise
first is app(p,s) =
T, if attrValue(identity.p) {APP}
F, otherwise
each of which in turn checks the identity of the first
(p) and third (n) node in a second entry of a flow in
some configuration table (In all of these definitions,
identity.e as an attribute of node e carrying its identity,
e.g. IP/MAC address, name, number etc.).
We can now give a definition of the θ permission
policy in terms of the above soundness conditions:
θ = {C1,C2,C3,C4}
Using the above θ, we can optimise a BAN network
configuration from one which is overly connected (i.e.
cf
ban
) to one which is more compact but is still a
permitted configuration (i.e. it maintains the sound-
ness conditions above). For example, the following
cf
smallban
table is one such compact network:
fid pid sid nid
------ ------- ------ ------
1 -- APP CWiFi
1 APP CWiFi D2
1 CWiFi D2 --
2 -- D2 CWiFi
2 D2 CWiFi SRV
2 CWiFi SRV --
4 -- APP CWiFi
4 APP CWiFi D1
4 CWiFi D1 --
6 -- D1 CWiFi
6 D1 CWiFi SRV
6 CWiFi SRV --
which maintains the connectivity between both D1
and D2 with their app and the back-end server, how-
ever only using the WiFi access point, and hence pro-
ducing a smaller network than that produced by cf
ban
.
Such a smaller BAN can be considered to be more op-
timum in the sense of its energy consumption; both
D1 and D2 will consume less energy as they are not
required to operate 3/4/5G connectivity.
6.2 Prohibited Policies
We turn now to the case of prohibition policies.
Let’s consider the scenario where neither device
D1 nor device D2 are connected to the server for a
prolonged period of time (set by the health carers
at the environment where person being monitored
is placed). A policy to prohibit this scenario can be
expressed as follows:
θ F (cf
ban
cf
ban
)
where cf
ban
= cf
ban
\{2,3,6,7,8}. In other words, we
are prohibited from changing the configuration table
cf
ban
above to a new one where flows 2, 3, 6, 7 and 8
are removed and no new flows added to ensure some
form of connectivity between either D1 or D2 and
SRV. The definition of θ would be the following:
θ = {C5}
where C5 = C1 C2, and C1 and C2 are as defined
in the previous section. In other words, we are pro-
hibited from changing a configuration table into one
which violates either condition C1 or condition C2,
meaning that both devices are disconnected from the
server. A stronger prohibition condition would re-
quire that both devices be connected to the server.
This would be expressed as C5 = C1 C2 (which in
this case is different from setting θ = {C1,C2}).
In real terms, what the above prohibition policy
gives us is a fail-safe criticality condition (i.e. C5),
which ensures that no new configuration tables are
constructed such that all/some health monitoring de-
vices become disconnected from the back-end server.
6.3 Obliged Policies
In our third example, we demonstrate how an obli-
gation policy can ensure that a desired status of the
network connectivity is eventually reached. Let’s as-
sume the network was initially configured using the
table of cf
smallban
defined earlier. In other words, that
both D1 and D2 are reachable only via the WiFi ac-
cess point. However, consider a new situation where
D1 becomes suddenly unreachable via WiFi (e.g. due
to some internal D1 malfunction or an issue with the
WiFi access point). This would result in a new con-
figuration table, call it cf
smallban
, which the network
transitions to as a correct reflection of the current net-
work state:
ICISSP 2025 - 11th International Conference on Information Systems Security and Privacy
338
fid pid sid nid
------ ------- ------ ------
1 -- APP CWiFi
1 APP CWiFi D2
1 CWiFi D2 --
2 -- D2 CWiFi
2 D2 CWiFi SRV
2 CWiFi SRV --
Again, we may have a fail-safe obligation policy,
defined as follows:
θ = {C1,C2,C3,C4}
where we can see that C1 cf
smallban
as well as C3
cf
smallban
, therefore triggering the obligation policy
via either of these two violations.
Now, in order to rectify this violation, we must
reconfigure the network to a safe configuration that
does not further trigger our obligation policy. One
example of such safe configuration is the following,
which refer to as cf
′′
smallban
:
fid pid sid nid
------ ------- ------ ------
1 -- APP CWiFi
1 APP CWiFi D2
1 CWiFi D2 --
2 -- D2 CWiFi
2 D2 CWiFi SRV
2 CWiFi SRV --
5 -- APP C4G
5 APP C4G D1
5 C4G D1 --
7 -- D1 C4G
7 D1 C4G SRV
7 C4G SRV --
This new configuration does not trigger the obligation
policy θ since C θ : C cf
′′
smallban
. The connectivity
to D1 is restored via the 4G connection point.
7 POLICIES FOR QUALITY OF
CONNECTIVITY
In addition to the examples we mentioned in the
previous section, it is also possible to use deontic
policies to manage network configurations based on
quality of connectivity (e.g. transmission bandwidth)
levels. Let’s start first by refining the four soundness
conditions C1–C4 we defined earlier in Section 6.1:
C1
c
: flow cf
smallban
: flow.2 = (p,s,n)
(first is device D1(p,s) second is server(s,n)
(attrValue(identity.s) = attrValue(identity.c)))
C2
c
: flow cf
smallban
: flow.2 = (p,s,n)
(first is device D2(p,s) second is server(s,n)
(attrValue(identity.s) = attrValue(identity.c)))
C3
c
: flow cf
smallban
: flow.2 = (p,s,n)
(second is device D1(s, n) first is app(p, s)
(attrValue(identity.s) = attrValue(identity.c)))
C4
c
: flow cf
smallban
: flow.2 = (p,s,n)
(second is device D2(s, n) first is app(p, s)
(attrValue(identity.s) = attrValue(identity.c)))
The new variations C1
c
C4
c
are parameterised by
the variable c. This variable is defined as c
{C3G,C4G,C5G,CWiFi}. In other words, the new
stronger conditions perform an extra check as to
whether the connection node, s, is the one supplied
by the condition. Informally, this means that the con-
dition holds if and only if the original soundness con-
dition is true in addition to having the correct type of
connectivity (i.e. 3/4/5G/WiFi).
This strengthening of the soundness conditions
allows us to set up a quality of connectivity ordering
relation, , defined as follows:
C3G C4G C5G CWiFi
which essentially says that 3G is lower quality than
4G, 4G lower quality than 5G and 5G lower quality
than WiFi. It is worth noting here that this defini-
tion of the quality of connectivity ordering is only one
example. One may define the ordering in a different
manner, depending on the definition of the business
scenario at hand.
Based on the above definition of , we can define
another order on the possible instances of our varied
soundness conditions C1
c
C4
c
above, as follows:
(Cn
c
C
Cn
c
) (c c
)
where
C
is a quality of connectivity ordering on the
soundness conditions and n = 1...4. For example,
we consider that D1’s connection to the server would
be of higher quality over 5G than over 4G:
C1
C4G
C
C1
C5G
since C4G C5G. This in turn leads to the emer-
gence of deontic policies, which are entirely based on
the ordering on these conditions.
Table 1 illustrates an example of different sub-
scription packages that a healthcare monitoring sys-
A Deontic Logic Model of Attribute-Based Information Flows in Database-Defined Networks with Application to Healthcare Monitoring
339
tem might be set up with as offered by a health-
care provider in association with a telecommunication
company, and the mapping of these packages to their
associated obligation policies.
Table 1: Different subscription packages and their mapping
to obligation policies.
Subscription Package Obligation Policy θ
Gold {(C1
C5G
C
C1
c
),
(C2
C5G
C
C2
c
),
(C3
C5G
C
C3
c
),
(C4
C5G
C
C4
c
)}
Silver {(C1
C4G
C
C1
c
),
(C2
C4G
C
C2
c
),
(C3
C4G
C
C3
c
),
(C4
C3G
C
C4
c
)}
Bronze {(C1
C3G
C
C1
c
),
(C2
C3G
C
C2
c
),
(C3
C3G
C
C3
c
),
(C4
C3G
C
C4
c
)}
From these, we can see that a Gold subscription
ensures that the quality of connectivity of the BAN
at the patient’s environment is better than 5G connec-
tivity. On the other hand, Silver subscription ensures
that that quality is better than 4G. Finally, a Bronze
subscription guarantees only better than 3G quality of
connectivity.
8 CONCLUSION
In this paper, we presented an attribute-based infor-
mation flow framework for the specification of de-
ontic policies (authorisation, prohibition and obliga-
tion policies) in DDN systems. We demonstrated
how such a formal framework can be used to specify
soundness properties in BAN networks based on de-
ontic logic, and provide richer semantics for describ-
ing the quality of connectivity in such systems.
Our research will facilitate the next step in inves-
tigating how risk can be modelled in such networks,
as well as other healthcare inter-connected systems.
Another area of future work will be to integrate ma-
chine learning techniques to enhance the potential of
SDN/DDN systems, especially in optimising network
configurations dynamically (e.g. as in (Arya et al.,
2024)). We plan to build datasets of historical DDN
configuration tables and use these to learn to predict
future tables, guided by our soundness properties, as
well as other properties that would be more difficult
to express, e.g. non-functional properties. Finally,
we also plan to focus on the role of the secure and
trusted-by-design smart contracts as applied to the
healthcare sector, e.g. (Dargaye et al., 2024), where
we can use such contracts to enforce compliance with
policies related to patient data access by ensuring that
historical configuration tables adhere to such policies
as recorded in past transactions (i.e. configurations),
and where the smart contract will be used to reward
normal and punish abnormal configurations leading
to higher quality SDN management.
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APPENDIX
The research presented in this paper is partly funded
by Innovate UK/Eureka CELTIC project ADA (award
number 10098971).
A Deontic Logic Model of Attribute-Based Information Flows in Database-Defined Networks with Application to Healthcare Monitoring
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