FastTriaje: A Mobile System for Victim Classification in Emergency
Situations
Alexandra Rivero-Garc
´
ıa, Candelaria Hern
´
andez-Goya, Iv
´
an Santos-Gonz
´
alez and Pino Caballero-Gil
Department of Computer Engineering, Universidad de La Laguna, Tenerife, Spain
Keywords:
Triaje, FastTriaje, NFC, Android, Elliptic Curves, Lightweight Cryptography, Internet of Things, Zero
Knowledge Proofs.
Abstract:
The high penetration of communication technologies and smartphones may help in many complex scenarios.
This work presents a system to perform victim diagnosis in emergency situation and/or natural disasters. The
implementation include a web platform, a web service and a mobile application. The synergy among these
three elements and different communication technologies such as NFC and Wi-Fi allows to classify potential
casualties in a fast, useful and reliable way. Robust cryptographic methods are used to ensure the access only
to legitimate users.
1 INTRODUCTION
The system proposed in this paper is called FastTriaje
and it is based on the method START (Simple Triage
and Rapid Treatment) (Iserson and Moskop, 2007).
This method allows to obtain two essential aims in an
emergency situation and/or a natural disaster: saving
as many lives as possible and optimizing the avail-
able resources, both material and human ones (Ra
´
ul
S
´
anchez Bermejo, 2011), (no, ).
A traditional triage helps to decide on patient’s at-
tention priority by means of three actions: Inspection,
Evaluation and Decision. With FastTriaje the disgno-
sis process is completely guided by the application.
The system itself will indicate to the diagnostician the
result of the evaluation and the decision to be carried
out.
One of the system elements is a mobile applica-
tion for Android devices. The application will be the
diagnosticians tool to classify the victims and storing
the information of each triage in an NFC tag that will
be attached to the victim. The tag generated may be
accessed at any time afterwards through the same ap-
plication.
The second pillar in the system is a web platform
whose main objectives are centralizing the triage in-
formation and easing user management.
The mobile application and the web platform in-
teracts by means of a REST web service, through the
transmission of different messages in JSON format.
Important security measures, based on lightweight
cryptography and zero knowledge proofs have also
been included improving reliability.
2 VICTIM CLASSIFICATION:
TRIAJE SYSTEMS
The word TRIAGE is a term recently coined by the
scientific community referring to patient classifica-
tion. A commonly accepted definition follows: a sim-
ple, completed, objective and fast process to obtain
an initial clinical assessment of people with the ob-
jective of evaluate their immediate survival capacities
and prioritizing them according their severity.
An efficient method for casualty classification in
a hostile situation is crucial. In order to achieve the
classification, all triage systems distinguish two steps:
• First triage or simple triage. It is carried out in
the hostile zone with fast methods like SHORT,
START (Simple Triage and Rapid Treatment)
or MRCC (M
´
etodo R
´
apido de Clasificaci
´
on en
Cat
´
astrofes). Here, the diagnostician will not
spend more than a minute, evaluating the survival
capabilities of victims and sorting them depend-
ing on their seriousness.
• Second triage. It is made in a medical station or
in a hospital. At this point, medical staff ana-
lyze each patient state: bruises, wounds and in-
juries. The Andorran Triage Model (MAT), Span-
ish Triage System (SET) and Manchester Emer-
238
Rivero-García A., Hernández-Goya C., Santos-González I. and Caballero-Gil P..
FastTriaje: A Mobile System for Victim Classification in Emergency Situations.
DOI: 10.5220/0004981502380242
In Proceedings of the 10th International Conference on Web Information Systems and Technologies (WEBIST-2014), pages 238-242
ISBN: 978-989-758-023-9
Copyright
c
 2014 SCITEPRESS (Science and Technology Publications, Lda.)

gency Triage System (METS) are methods widely
used during this stage.
Note that two types of triages are defined but they
are not mutually exclusive, both should be carried out.
The first triage gives important information about pri-
orities for evacuation to hospitals where medical staff
will do the second triage.
A more detailed description of the START method
(Simple Triage and Rapid Treatment) has been in-
cluded bellow because is the one used by FastTriaje,
(see figure 1).
Figure 1: Simple Triage and Rapid Treatment Algorithm.
START method consists of answering a few sim-
ple questions to evaluate possible casualties. The an-
swers are just “Yes” or “No” and depending on the
answer given, the method will make another question
or establish a classification. The questions are related
to:
• mobility,
• breathing,
• perfusion, and
• state of mind.
START uses colored tags in the classification, each
color stands for a different seriousness level:
• Black: dead or irrecoverable victims.
• Red: victims requiring immediate care.
• Yellow: victims requiring urgent care, but can
wait for treatment from half an hour to one hour.
• Green: victims who are not seriously injured.
They can wait for treatment more than an hour.
The traditional colored tags, are substituted by NFC
tags. Next this technology and its security counter-
measures are introduced.
3 NEAR FIELD
COMMUNICATION
TECHNOLOGY
Near Field Communications or NFC (nfc, b) is a
short-range high frequency wireless communication
technology. It may be defined as an extension of
Radio Frequency Identification (RFID) since it com-
bines the interface between tags and reader into a sin-
gle device. It allows users to share content between
digital devices in a peer to peer mode what makes it a
promising paradigm in mobile technology.
In 2003 NFC was approved as ISO standard and
nowadays is a technology used in many applications
like car keys, ID cards, tickets, smartphones and so
on. Contrary to other technologies as RFID, Blue-
tooth, ZigBee or Wi-Fi, NFC is not designed to send
information continuously. Communication between
devices requires that devices touch each other to ex-
change the information quickly and timely.
Some key features of NFC are:
• Its frequency range is 16.56MHz, this is a free fre-
quency.
• Different communication rates are allowed:
106kb/s, 212kb/s or 424kb/s.
• High proximity between devices is needed: 10cm
or less.
• It is an open technology based on standards.
• It may be considered a simple and reliable tech-
nology.
• Two communication modes are supported: active
and passive mode. The first one allows commu-
nication between devices that can generate their
own magnetic camp. The second is devoted to the
interaction with NFC tags.
One of the main advantages of NFC when compar-
ing it with other technologies is its inherent security.
Due to its short communication range and the need of
user involvement when an action is performed, NFC
provides a higher security level.
A comparison among different technologies has
ben included in Table I ((nfc, a)).
4 FastTriaje SYSTEM
FastTriaje main scenario is an emergency situation or
natural disaster. Its goal is to speed up the classifica-
tions of victims. The modules that compose the whole
system may be appreciated in figure 2: a mobile ap-
plication and a web platform.
FastTriaje:AMobileSystemforVictimClassificationinEmergencySituations
239

Table 1: Comparison of some short range technologies.
Technology
Feature NFC Bluetooth RFID ZigBee
Connection set 0.1s or less 6s 0.1s or less 30ms
Speed 424-848kbps 24Mbps (version 3.0) 424kbps 250kbps
Range 10cm 10m 3m 70m
Battery consumption Low High Low Low
Security High High Vulnerable Vulnerable
User experience Touch Need configuration No configuration No configuration
Figure 2: FastTriaje modules.
A mobile application is included. The main goal of
this Android application is implementing the START
triage method in mobile devices as a simple, usable
and intuitive tool that facilitate the traditional triage
process. All the triages generated are sent to a web
platform, where every user has access to the informa-
tion associated to the triages made by him/her. Addi-
tionally, the application allows to store each triage on
an NFC tag to label victims.
Only legitimate users can exchange information
with the web platform since a robust authentication
protocol (see ZKP1 in next section) is used before
transferring triages. All users who want to use the mo-
bile application must be registered in advance on the
web platform. User’s privileges are set by the system
administrator on this platform. Thus, it makes pos-
sible to distinguish between users with permissions
to only read tags from those who may write on it, as
well.
The web platform communicates with the mobile
application by means of a web services. Before writ-
ing information on a NFC tag, the authorized user
executes another authentication protocol (ZKP2) that
associates the triage to be stored there with his/her
credentials.
5 LIGHT WEIGHT
CRYPTOGRAPHY AND ZERO
KNOWLEDGE PROOFS
Nowadays mobile applications are designed for al-
most any field: business activities, transport manage-
ment, social sharing and so on. In all of them guar-
antying information security is a must. Traditional
solutions generally need specific infrastructure, trans-
ferring these solutions to the environment under study
here is non-viable (Babar et al., 2010).
We have used lightweight cryptography in order to
guarantee legitimate access to the information associ-
ated to the triage system. Concretely, we use Elliptic
Curve Cryptography (ECC) (Hankerson et al., 2003)
since:
• it provides with problems with higher computa-
tional complexity, and
• key length to achieve certain security level is
shorter.
When using ECC there is certain notation related
to the curves used that should be defined. This nota-
tion is included in table II.
E(F
p
) = {(x, y) ∈ F
p
xF
p
: y
2
= x
3
+ ax + b} ∪ {O}
(1)
where
a, b ∈ F
p
, 4a
3
+ 27b
2
̸= 0
Table 2: Elliptic curve domain parameters in ZKPs.
Parameter Description
p prime number defining
the field F
p
a, b coefficients in the equation
of elliptic curve E
P a base point (a generator of
a cyclic subgroup of E(F
p
))
m order of P in E(F
p
)
This election is justified by the restrictions on the
computational and communication capabilities de-
fined on the devices involved, smartphones mainly.
The solutions developed are based on Zero Knowl-
edge Proofs (ZKP) which stand out as a promising
solution to the authentication problem in the Internet
of Things (Mart
´
ınez et al., 2009), (Ramzy and Arora,
2011), (Alp
´
ar et al., 2012).
These protocols allow a party A to convince an-
other party B, about the knowledge of certain se-
cret information without sending anything related to
WEBIST2014-InternationalConferenceonWebInformationSystemsandTechnologies
240

it. These demonstrations may be extended to solve
the authentication problem as it isincluded in the ISO
standard 9798-5 dedicated to entity authentication.
ZKPs use three main elements:
• Witness (w): the prover selects a random item
from a predefined set, keeping it secret. This value
is called compromise (x). From it, the prover gen-
erates a value called witness, and then, sends it to
the verifier.
• Challenge (e): In the second step, the verifier se-
lects a random question that must be answered by
the prover correctly, provided that he/she knows
the secret information. This question is related to
x and with the secret associated to the credentials
of the prover.
• Answer (y): Finally the prover sends a response
to the challenge and it is now when the verifier
analyzes that response and checks if it is correct,
in this case the authentication is accepted.
6 AUTHENTICATION METHODS
IN FastTriaje
This section describes the authentication protocols
implemented in FastTriaje to guarantee access con-
trol only to legitimate users. The two first protocols
share certain features, for example both protocols are
interactive (two parties, the prober A and the verifier
B takes part) and the bootstrapping stage consists of
defining an elliptic curve E and a base point P on it.
Apart from that, the credentials associated to A are
defined in the same way: the secret identification is
an integer randomly selected in Zp, while the public
one is a point on the curve E generated by multiplying
the secret integer by the base point.
6.1 ZKP1 One-way Authentication:
First Proposal
This protocol is devoted to authenticate mobile de-
vices (A) against the web platform (B). A detailed
description is included in Table III. It makes use of
a hash function to define the challenge in each exe-
cution. This feature does not corresponds with the
original definition of ZKPs but allows to reduce the
number of iterations to just one in each authentication
interaction.
Table 3: ZKP1.
Stages Actions
Bootstrapping p prime number
E elliptic curve in Z
p
P ∈ E
A’s secret a ∈ Z
p
identification
A’s public a ∗ P ∈ E
identification: PuidA
Compromise: A’s secret x ∈
r
1
Z
p
Witness: A → B w = x ∗ P ∈ E
Challenge: A ← B e = hash(P, a ∗ P, x ∗ P)
Answer: A → B y = x +a ∗ e ∈ Z
p
Verification: B checks y ∗ P − e ∗ PuidA = w
6.2 ZKP2 One-way Authentication:
Second Proposal
The protocol described here is used to authenticate
a user (A) against an NFC tag (B) prior to storing a
triage on it.
Table 4: ZKP2.
Stages Actions
Bootstrapping p prime number
E elliptic curve in Z
p
P ∈ E
A’s secret a ∈ Z
p
identification
A’s public a ∗ P ∈ E
identification: PuidA
Compromise: A’s secret {x
1
∗ P, x
2
∗ P, · ·· , x
n
∗ P}
∈ E, with x
i
∈
r
Z p
Witness: A → B w = hash(x
j
∗ P + x
k
∗ P),
with j, k ∈
r
{1, 2, · ·· , n}
Challenge: A ← B e ∈
r
Z p
Answer: A → B y = x
j
+ x
k
− a ∗ e ∈ Z
p
Verification: B checks hash(y ∗ P −e ∗ PuidA)
= w
However this protocol cannot be used directly on
the NFC tags since they are totally passive, making
it impossible for them to generate challenges. That
is the reason why the the Fiat-Shamir Paradigm (Fiat
and Shamir, 1987) has been used to transform the in-
teractive ZKP2 into a non-interactive ZKP. The new
protocol is described in Table 5.
Applying this paradigm requires the definition of
the challenge by using a hash function. We have opted
by using the new standard SHA3 (Bertoni et al., ).
FastTriaje:AMobileSystemforVictimClassificationinEmergencySituations
241

Table 5: ZKP2 Non interactive.
Stages Actions
Bootstrapping p prime number
E elliptic curve in Z
p
P ∈ E
A’s secret a ∈ Z
p
identification
A’s public a ∗ P ∈ E
identification: PuidA
Compromise: A’s secret {x
1
∗ P, x
2
∗ P, · ·· , x
n
∗ P}
∈ E, with x
i
∈
r
Z p
Witness: A → B w = SHA3(x
j
∗ P + x
k
∗ P),
with j, k ∈
r
{1, 2, ··· , n}
Challenge: A ← B e = SHA3(w) ∈ Z
p
Answer: A → B y = x
j
+ x
k
− a ∗ e ∈ Z
p
Verification: B checks SHA3(y ∗ P −e ∗ PuidA)
= w
7 CONCLUSIONS AND FUTURE
WORK
A system that may improve logistics, the classifica-
tion and attention of casualties in hostile situations
such as natural disasters or accidents have been devel-
oped. The tool consists of a mobile application and
a web service. The mobile application performs the
triages and allows to store the results on NFC tags,
that may be attached to victims. It is also possible
to transfer them through a web service to a central-
ized web platform where the information may be pro-
cessed according different user profiles.
Since the services provided are critical, security
on data communication and reliability requirements
have been taken into account.
There are still some points in the system than can
be improved, such as:
• Adding statistical functionalities to the web plat-
form.
• Integrating it with patient’s clinical records.
• Extending the application to perform the second
kind of triage.
ACKNOWLEDGEMENTS
This research has been partially supported by the
Spanish Ministry of Economy and Competitiveness
and Ministry of Science and Innovation under grants
IPT-2012-0585-370000: DEPHISIT and TIN2011-
25452: TUERI.
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