International Journal of Soft Computing and Engineering

International Journal of Innovative Technology and Exploring Engineering (IJITEE)

ISSN: 2278-3075 (Online), Volume-8 Issue-10, August 2019

1253

Published By:

Blue Eyes Intelligence Engineering

and Sciences Publication (BEIESP)

Retrieval Number: H7024068819/19©BEIESP

DOI: 10.35940/ijitee.H7024.0881019

Journal Website: www.ijitee.org

Abstract: Software become an unavoidable in every once life.

Quality of the software is an import aspect in the software

development life cycle. Quality for a software is represented in

terms of functional and non-functional requirement. Software

architecture is used to represent the using set of components and

is connectivity as a relationship between these components. To

assure the development process meet the requirement given by the

user, the Software Evaluation is used. Early detection of error

protect the software development producing the defect software.

ATAM is the one of the method used to detect the risk, non-risk,

scenarios and tradeoff in the earlier stage of development life

cycle. Here in this paper security scenarios for mobile application

has been elicited and compared with the scenarios extracted from

the whatsapp application. Comparison shows few scenarios need

to added with existing scenarios in order to improve / ensure full

security for the metadata.

Keywords: ATAM, Software Evaluation, Whatsapp;

I. INTRODUCTION

Quality software are developed by designing quality

software architecture. Quality has been maintained by

analysing the architecture during the development process of

the software architecture[4]. The given problem statement

and requirement specification are taken as the metrics against

which the software architecture is evaluated. Very high-level

design of large software are described using software

architecture. Overall structure of the software is expressed as

abstract, structured manner in the software architecture.

Identifying the major components and the interaction

between these component is the main goal of software

architecture. Software is developed to meet the set of user

requirements. User expectations are described as functional

requirements in terms of services. The quality of these

services is specified as non-functional requirements. A

formal definition given by Sommerville [1996] states that

“Software engineering is concerned with the theories,

methods and tools for developing, managing and evolving

software products.” Requirements engineering, design,

programming, integration, delivery, and maintenance are the

six processes of software life cycle. It is very important to

perform the requirement engineering properly, otherwise the

developed software not useful for the end user even though

the code run properly. Software Requirements Specification

(SRS) document is a formal document where the

specifications for the new software product written.

Manuscript published on 30 August 2019.

*Correspondence Author(s)

Almas Begum, Assistant Professor, Research Scholar,

Vel Tech Rangarajan

Dr. Sagunthala R & D Institute of Science and Technology

Cyrilraj, Dr. M. G. R. Educational and Research Institute

Sciences Publication (BEIESP). This is an open access article under the

CC-BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/

Design of the software system is the next step, this is

the beginning stage of the Software Architecture. Software

Architecture to be the high-level design stage and it is

software design at the highest level of abstraction.

Representation of the architecture is an important aspect.

Success of the succeeding steps in the software development

is in representing the architecture clearly. Software

architecture can be represented as various methods of

diagrammatic and descriptive. Set of components and

connectors are defined with relationships between different

components is represented as Software Architecture. In

addition, a software architectural description of a system may

have many different external agents, commonly called

“stakeholders” [Bass, L. et.al 1998, P. Clements et.al 2002,

IEEE 2000, Kruchten P. 1995], and each stakeholder may

have different expectations and requirements from the same

system. Wolf [Perry, D et.al. 1992]defines the “Software

Architecture = {Elements, Form, Rationale}, A Software

Architecture is a set of design elements that have a particular

form.” Architectural design is motivated by three arguments

[Bass.L et al 1998]. First, At very early stage of the design

process stakeholders discuss about an artefact. Second, it

allows for early assessment or analysis of quality attributes.

Finally, the decisions captured in the Software Architecture

can be transferred to other systems. Commonly used

definition for “Software Architecture is “It is a program or

computer system is the structure or structures of the system,

which comprise software components, the externally visible

properties of those components, and the relationships among

them”[Bass.L et al 1998]. [M. Shaw 1990]”. Software

Architecture is an abstraction of the runtime elements of a

software system during some phase of its operation. A system

may be composed of many levels of abstraction and many

phases of operation, each with its own software architecture”.

Is the another well-known definition of Software

Architecture. Following perspectives are covered in the early

design of Software Architecture, they are system

functionalities of the domain are decomposed, system

structures are divided into components and their interactions

are defined, and allocation of functionality to that

architecture[R. Kazman et.al 1994].Software architectural

Evaluation provides assurance to developers that given

architecture will meet the requirements in terms of both

functional quality and non-functional quality, it also assures

that understanding of architecture, detection of defects with

early architecture. Software architectural Evaluation has

some limitation commonly

Almas Begum, Cyrilraj

Architecture Evaluation of Mobile Application:

Architecture Evaluation of Mobile Application: Whatsapp

1254

Published By:

Blue Eyes Intelligence Engineering

and Sciences Publication (BEIESP)

Retrieval Number: H7024068819/19©BEIESP

DOI: 10.35940/ijitee.H7024.0881019

Journal Website: www.ijitee.org

• To take out the important scenarios, there are no

systematic methodologies exists

• Clients requirements specification and stakeholders

are not covered fully

• During evaluation the accessibility is very poor, need

to access more related documents in same or similar

projects

View is used to organize the software architecture

description, they are analogous to different types of

blueprints made in building architecture. Set of system

components and its relationships are represented as views.

The notations, modelling techniques are specified in the

viewpoint and used in view that express the architecture in

the form of questions which collected from the set of

stakeholders. The view point also specifies the presentation,

model kinds used, conventions used and any consistency

rules to keep a view consistent with other views. Software

Architecture is a combination of components, connectors and

connections. From the smaller subparts or components

Architecture- based software are assembled into a system.

Identify the essential subparts of the system under

consideration is the very important task. After identifying the

subparts, then find out how different subparts are

communicate and is there any dependability exist?. The

following external components such as people, other

software systems, other hardware systems are having interest

in the software system, and affect the system, are called

“Stakeholders”. The view, interest on the system and

requirements of different stakeholders may differ. In order to

bring into a maximum requirement satisfaction, architect

need to balance between different stakeholders requirement.

The perspectives from different stakeholders over view of the

software architecture will differ from each, In traditional

these perspectives are called as architectural views. Same

system can be viewed in different Viewpoint from different

stakeholders, the whole description of the architecture

defined by combining these views. The following are the

objectives of the architectural representation a. Based on the

requirement designing different views, b. Represent full

architecture by combining all views. The rest of the paper

arranged as session 2 introduces the architecture of whatsapp,

session 3 explains about representation of whatsapp

architecture in terms of UML diagram and scenarios for

security. Session 4 explains about the evaluation methods and

finally comparison of scenarios

I. WHATSAPP ARCHITECTURE

Message communication over mobile phone was started with

SMS, when the communication medium reaches third

generation the message communication between mobile

phones makes use of applications like Whatsapp, Viber,

Skype, Line, Hangout etc. Among these applications

Whatsapp dominates and catch a permanent place for

messaging service. Every day number of users added as a

customers and total number of users crossed 1.5 billion.

Apart from messaging whatsapp gives voice calling, video

calling, group chatting with maximum of 100 members in a

group. Whatsapp makes use of the contacts to communicate

with others with the permission of user. Also makes use of

camera to take photos, gallery store data such as images and

videos.

Fig 1: XMPP Server

XMPP server (XMPP-Extensible Messaging and Presence

Protocol) server used by the Whatsapp. To transfer message

between the open source Ejabberd has been used, it transfer

messgaes between two or more user at any point of time[3].

Whatsapp make use of both HTTP and XMPP for the

communication. XMPP used during asynchronous federated

limited purpose communication whereas HTTP used

synchronous unfedered general purpose communication.

XMPP vs HTTP

Fig 2: Comparison between XMPP vs HTTP

II. UML REPRESENTATION OF WHATSAPP

ARCHITECTURE

Components of the whatsapp and communications between

them can be represented using following UML diagrams[5].

Use Case representations:

Fig 3: Use Case diagram for Whatsapp Messaging

Fig 4: Use Case diagram for Whatsapp Profile/Status

Ejabberd

XMP

XMPP

Client

XMPP

Server

XMPP

Server

XMPP

Client

HTTP

Client

HTTP

Server

HTTP

Server

HTTP

Client

International Journal of Innovative Technology and Exploring Engineering (IJITEE)

ISSN: 2278-3075 (Online), Volume-8 Issue-10, August 2019

1255

Published By:

Blue Eyes Intelligence Engineering

and Sciences Publication (BEIESP)

Retrieval Number: H7024068819/19©BEIESP

DOI: 10.35940/ijitee.H7024.0881019

Journal Website: www.ijitee.org

Fig 5: Use Case diagram for Whatsapp Call

Fig 6: Class Diagram for whatsapp

Fig 7: Sequence Diagram for whatsapp

III. ARCHITECTURE OF WHATSAPP

SECURITY

A long term key stored in the device memory, A shared

key generated using this long term key and used to make a

secured communication between another user[1]. A

permanent communication channel was established between

two user and this channel remains until reinstalled or device

changed[2]. Man in the middle attack will be reduced with

signal protocol because it uses Diffie–Hellman (D-H) key

exchange method in each key generation on Off-the-recorded

(OTR) based mechanism and ensures that no MITM attack is

possible on any of the subsequently generated keys. There is

a security concern when storing the data in the user device, it

is not encrypted which will leads a lack in the security.

Whatsapp makes use of the cloud server to backup, also

makes use of google, amazon iCloud. There is no guaranty

that these servers stores the data with encryption which may

leads to data leaks. When the device theft, there no security

for the past communicated data. Meta data is the another

concern in terms of security. WhatsApp creates the

end-to-end encryption to establish the communication

channel between users. When the meta data of the user

encrypted during transmitted through the communication

channel. Company terms allows to exchange the user data

between two user when a communication channel

established. Entire contact list will be share to other app with

the permission of user. The following scenarios for

security has been extracted for whatsapp mobile application

IV. SECURITY SCENARIOS

S1: Authenticate the user with mobile number and otp

S2: Encrypt the data such as transit, phone numbers,

timestamps, connection

duration, connection frequency and user location must be

stored to servers for future

retrievals

S3: Ensures that the message sender or receiver cannot be

irrefutably

S4: Communication channel between users using end-to-end

encryption

S5: Allow to share entire contact list with the app

S6: Swapped the following information between the two

parties: time of delivery, mobile

phone numbers involved in the messages, size of any digital

content

Table 1. Comparison with Elicited Scenarios with Existing

Whatsapp Scenarios: Security[6][7]

Concern

Proposed

Extracted

Status

Authentication &

Authorization

Must be provided

in order to avoid

leakage of

sensitive data.

Available

Configuration

Once restoration is

done, design

should be able to

reset the

configuration

Available

Validation

Design must

provide validation

to reduce bugs

caused by invalid

data, refuse access

to malicious

attacks- not

filtering invalid

characters

Available

Synchronization

Over-the-air

methods has to be

considered to

synchronize data

Need to

include

Memory Limitations

Binary format can

be used to

configure files

when memory is

limited. Binary

representation can

also be used to

store objects.

Need to

include

Location

Authorized Data

access must be

enabled when

sensitive data is

accessed from a

different location.

Architecture Evaluation of Mobile Application: Whatsapp

1256

Published By:

Blue Eyes Intelligence Engineering

and Sciences Publication (BEIESP)

DOI: 10.35940/ijitee.H7024.0881019

Journal Website: www.ijitee.org

Avoid invalid

access to any

service that can be

vulnerable to

sensitive data

Communication

Declining to

defend sensitive

data, failing to

resolve

untrustworthy

scenarios

Layer

Components must

be grouped

properly in

appropriate layers.

Need to

include

Data access

Proper data access

mechanisms have

to be implemented.

Care must be taken

when accessing

large data sets are

accessed. Avoid

unnecessary

access to open

database with long

time waiting.

Device

considerations

have to be

considered for

aspects such as

memory, storage

space, network

bandwidth, size of

the screen at the

time of design.

Need to

include

From the above table the security concern for the

Synchronization, Memory Limitations and Layer need to

include. Further to improve the efficiency of the usage of app,

the following facilities can be included. An option of

selectively adding contacts to the WhatsApp list. There must

be some condition that can stop its parent company using

information gathered through the whatsapp. Need to add

security for the metadata in case of device theft.

V. CONCLUSION

Software architecture is a representation of components and

connectivity between these components. In this paper ATAM

evaluation to extract the scenarios for mobile application has

been used to compare with the security scenarios for the

whatsapp mobile application. The results shows the scenario

for the Synchronization, Memory Limitations and Layer need

to include in order to make sure the full security for the

application.

REFERENCES

1. Nidhi Rastogi and James Hendler, “WhatsApp security and role of

metadata in preserving privacy”

2. “WhatsApp Encryption Overview” Technical white paper

3. Umesh Gupta, “An Overview on the Architecture of Whatsapp”,

International Journal of Computer Science & Engineering Technology

(IJCSET), Vol. 7 No. 07 Jul 2016, pp 335-337

4. Ronan Fitzpatrick, “Software Quality: Definitions and Strategic

Issues”, Staffordshire University, School of Computing Report, April

1996.

5. Almas Begum and V. Cyrilraj, “Architectural Analysis for Improving

Security using LBS with ATAM” IJAER, ISSN 0973-4562 Volume

10, Number 8 (2015) pp. 19967-19975.

6. Rich Hilliard, “Using the UML for Architectural Description” Lecture

Notes in Computer Science, volume 1723, Springer

7. ios security guide –

“https://www.apple.com/business/docs/iOS_Security_Guide.pdf”

8. https://msdn.microsoft.com/en-in/library/ee658108.aspx

AUTHORS PROFILE

Almas Begum, M.E., CSE, currently working as an

Assistant Professor in Vel Tech Rangarajan Dr.

Sagunthala R&D Institute of Science and Technology.

She is also pursuing her research at Dr MGR

Educational and Research Institute

V Cyrilraj Ph.D currently working as Professor of

Computer Science and Engineering, ,Dr MGR

Educational and Research Institute