International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
Strengthen Cloud Computing Security with Enhanced Two
Factor Authentication and Encryption
Divya Saraswat*
M.tech CSE, IPEC(UPTU)
Dr. Pooja Tripathi
Professor CSE, IPEC(UPTU)
Abstract:
Cloud computing has become a buzzword that nearly everyone has heard but only few can truly
understand its correct meaning. Today, cloud has taken over the IT landscape. Cloud computing
refers to menu of hosting services usually provided over the internet on a usage or metered basis,
while at the same time leveraging infrastructure shared by multiple users. Cloud itself is maintained
by cloud service providers through networked “server farms”. They offer their subscribers unlimited
availability and data storage, along with the seamless access to software, application provisioning
and automatic upgrades. Security is one of the most concerning downsides while using cloud
services. As organisations and individuals store data in cloud and if this data isn‟t properly protected
loss and exposure can happen. Therefore confidentiality, authentication and access control are the
challenging factors in data security. Our work attempts to overcome these types of data security
concerns. In this paper to ensure authentication, a strong authentication mechanism using muti-step
authentication has implemented based on dynamic one time password technique. This technique is
very much secure, robust and highly efficient. The produced mobile token which is valid for only a
small session is used by client to authenticate itself. For data storage security and information
security over cloud AES-256 encryption and MD5 hashing is used. Access controls and permissions
on data accessibility are also gets implemented. Our work mainly deals with cloud computing
security model.
Keywords: AES, multi factor authentication, authentication, MD5, multi auth app, mobile token, and
access control.
I.
INTRODUCTION
Cloud computing is the defining technology of twenty first century as well as it defines utility just as
electricity was for twentieth. When we use any appliance that use electricity we think that power is
sufficient to run our appliance. What we don‟t know is that where and from what source power
comes from- whether it is from our nearby nuclear power plant or from hydroelectric facility or a
wind farm. Cloud computing is similar we know it will be there and is sufficient but we don‟t know
on what kind of hardware our data will be stored on, nor do we always know where it is stored on.
The cloud is basically computing power plant while the various cloud providers like Azure, Amazon,
Rackspace, Microsoft are computing power companies. Cloud computing offers incredible
processing power, very wide storage space and a high speed of computation. Cloud computing
technologies are categorized as- software as a service, platform as a service, infrastructure as a
service and data storage as a service[1]. The cloud models where they are deployed are also falls in
four categories: public cloud, private cloud, hybrid cloud and community cloud[2]. New challenge
around the security emerge when data on cloud is to be stored. Control over the data is one of the
primary need as it flows from one virtual machine to another. Traditional hardware based appliances
137
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
had no control over data once it is in cloud. Therefore it requires the use of virtual security appliance
to protect and maintain the data.There are various security layers, some of them are:
1.
Authentication: Authentication identifies a user. More clearly, authentication is process of
determining whether someone or something is, in fact, who or what it is declared to be.
Authentication level description:
a.
Single factor authentication: it require only one factor which “something user knows” like
username and password.
b.
Multistep authentication: requires multi step authentication process which must be executed
in consecutive order or sequence successfully.
Example: Gmail, BOX
c.
Two factor authentication: it is the subset of two step. it requires the use of only two factors
from the below list:
Something you know (password, pin)
Something you have (token, key)
Something you are (fingerprint, retina scan etc.)
Example: PKI system
d.
Multi factor authentication: it requires the use of three or more factors from below list:
Something you know (password, pin)
Something you have (token, key)
Something you are (fingerprint, retina scan etc.)
Example: key card entry system
2.
Authorization: Authorization provides authenticated users with permissions to certain
resources. These resources can be system objects like information, application programs etc.
3.
Encryption of data: encryption is core basis in cryptography. It is the process of transforming
information in an unreadable format or we can say it convert plain text into cipher-text and hence
become unreadable. Data stored on PC, tablet, smart phones can be encrypted based on type of data.
One of the biggest issue in cloud computing is that of security. As organisations and individuals
moving their data to cloud, the safety of their data is a crucial factor. The main objective of this
paper is to enhance data security for cloud computing. . For authentication security purpose instead
of only rely on username and password, an additional multi-auth-app has introduced which is based
on two factor authentication with multi steps for creating mobile token which is valid for one login
session or for short period. The generated mobile token is then used by client to authenticate itself for
using cloud services. The data storage security is implemented by using AES encryption technique. It
is a symmetric encryption technique and is very reliable and faster algorithm. This paper resulted in
authentication and registration method that is both secure. Permissions for access rights like grant or
deny on data are also gets implemented. MD5 technique is used for hashing client registration and
login details. Hashing is for verifying the contents of message. Hence, our approach also maintains
data integrity. In this paper we are going to present work and its implementation details using azure
cloud services.
This paper organized in following manner: section 2 reviews related work of authors.
Problem statement is given in section 3. Detailed proposed work presented in section 4. Requirement
specification provide in section 5.section 6 Shows the implementation work of the proposed work.
Section 7 concludes the paper.
138
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
II.
RELATED WORK
Various research has done in the field of security of cloud computing environment. Lin, Shen, and
Hwang [3] has proposed a strong password authentication scheme in which they discussed to make
use of smart cards. With the help of the proposed scheme they can resist guess attack, replay attack,
impersonation attack and stolen attack. Later on, W. C .Ku. [4] has proposed a hash-based strongpassword authentication scheme to enhance the security without using smart card. However, it still
has the some weakness and suffers attacks. As per Saxena [5] proposed a technique in which he
suggested to use one time password for authentication. The generated OTP was based on event
synchronization technique. Jing-Jang Hwang et al. [6], surveyed a business model for cloud
computing for data security using data encryption and decryption algorithms. In this method cloud
service provider has responsible for data encryption/decryption tasks for data storage and it results in
more computational overhead for process of data in cloud server. There is no control of data for data
owner in this type of scheme.
III.
PROBLEM STATEMENT
In vast majority of online experiences and logins, people mostly rely on Static passwords based on
only username and passwords which are easy to crack. The problem with this methodology is that
once you shared this secret it does not remains a secret. Security can be enhanced by using strong
authentication. Also as, data is stored anywhere in cloud and has no borders so this creates various
confidentiality, integrity and privacy issues in cloud environment and hence demanded a trusted
environment wherein data security can be maintained. In current approaches there are several issues
in authentication mechanism. The need is for determining a certain scheme that will provide
authentication, confidentiality and integrity to a single server.
IV.
PROPOSED WORK
This section describes a proposed data security model and focuses on enhancing security by using
two factor authentication with multi steps ,encryption, hashing, and access rights policy. The
security framework will take care of authorization and authentication, confidentiality and integrity of
user while accessing any cloud server.
Registration
Firstly users who want to access the cloud services have to register themselves. A registration form
have to be filled by them which include client information. All the user information now gets stored
in cloud database. As registration mechanism includes crucial information, this must be protected
from others. For the security purpose MD-5 hashing is used by the authors on registration
information. User information now gets stored in cloud where password and all the other details are
stored in hash format using MD-5 hashing so that any attack by malicious users would be ineffective
and hence also maintains integrity. Md-5 hashing is a one way system and is unbreakable[7].
Login and Data Authentication with multi steps
The authentication method used in our scheme is based on multi steps with two factor authentication
that add an extra layer of security to the existing schemes[8] and make it more stronger. Figure 1 and
figure 2 showing authentication and multi auth app flowchart.
139
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
USER
EXISTING
NON-EXISTING
USER
USER
ENTER
USERNAME &
PASSWORD
REGISTER WITH THE
SERVER
NO
IS VALID
YES
ENTER OTP
NO
IS VALID
YES
ACCESS TO USER
PROFILE
END
Figure 1. Flowchart showing AUTHENTICATION
140
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
Two factor with multi step authentication:
a.
In first phase a user firstly logs in his/her account by firstly providing details like something
you know. For example: when a user firstly wants to login, a username and password must be
required. These details are also gets stored in hash format.
b.
In second phase, multi auth app has created for providing access. Multi auth app is an
application that users have to install in their mobile phones. Cloud provider send OTP through this
app. This app also has various factors. As in traditional OTP based message anyone who has access
to others mobile phones can check the message that contains the otp information and use it illegally
but in this type of application to get a mobile token, the mobile owner firstly have to entered its own
created or updated password and then have to enter its mobile number on personal device interface
only then the user have gained an access to the mobile token or OTP.
FIGURE 2. Flowchart showing multi-auth-app
141
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
So as soon as user correctly entered the log in details in first phase, that user have to enter the OTP
which the users only gets through their mobile phones by using multi auth app means something you
have. This results in more extra credentials requirement for accessing mobile token. These extra
credential requirement like password for mobile device, mobile number are the multi steps of
authentication. This form strong security for accessing the OTP.
This multifactor authentication is much more safer than static password methods. The mobile token
or OTP generated is valid only for a very short duration time or you can say for only one session.
OTP are immune to password sniffing attacks. For example: suppose if a hacker use any software to
collect your data traffic or other valuable information, there is not to worry as the password he will
get will of no use.
This solution offers greater benefits when compared to other types of authentication solutions:

Username and the OTP are the only crucial information, sent over the network. Since the
OTP is only valid for very short time it will be of no value for an attacker.

PIN code is only known to the user which is used to generate the OTP on mobile phones.

The cost will be absolutely free for both user and provider, since this is an open source
solution.

The user only have to carry his mobile phone with him and their is no need to carry any extra
authentication device

Easy registration process where everything can be done from home, no need to order an
external authentication device or get the device from a local office.
As a result only authorized users can gain access to the cloud system.
Secure storing and accessing of data
After successful authentication, a user can now connect with the system. User can now have access
to file storage system.
For Encryption during file upload AES-256 has implemented in this application for secure data
storage on server. AES as compare to RSA, DSA, and RC4 is much better encryption technique
because its algorithm fast and reliable. AES-256 is symmetric key encryption technique. For other
information transmission including registration and login details MD-5 hashing is used.
Permissions
A permission is an authorization to perform an operation on a specific object, such as file. While
uploading data, permissions also gets applied on the data. These permissions can be granted to a
user, group, special identities, any trusted domain, or computer. In role based access control list,
permissions are assigned to roles. A user must be a registered member of that role. Permissions are
associated with roles not with users. Below table 1 shows an instance of the permission module. All
the data including access rights like allow and deny on a particular file also send in cipher form to
the server using AES encryption technique.
Current UID Search UID Add
Teacher
Teacher
No
Teacher
Student
Yes
Student
Student
No
Student
Teacher
Yes
Current UID can't search Own UID
Table 1. permissions on search and add of users
142
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
V.
REQUIREMENT SPECIFICATION
Hardware requirements
The system running the application should have following system requirements:

Intel(R) Core (TM) i3 CPU M370 @ 2.40 GHz

2.39 GHz processor,

3 GB of RAM

Microsoft Windows 7 Ultimate 62 bit Operating System

Android device such as smart phone or tablet
Software requirements

Android SDK

ADT Plugin

Some Android SDK packages

USB drivers

Java development kit(jdk)

Visual studio 2012
VI.
IMPLEMENTATION DETAILS
The system is implemented in two phases. For authentication security phase, multi auth app has been
created for android mobile phones. For multi auth app android developer tool is used. Eclipse is used
where xml is graphic user interface and java is a command user interface. In visual studio
environment c# is used as a backend language. We have also hosted this implemented model in
Azure cloud.
Module 1
The proposed system is divided into two parts:

Client

Server
Figure(3) shows the home page including login and registration sections.
Figure 3. Home page
143
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
Module 2: Registration of clients
Figure(4) shows new registration form for users. The form includes user id, password, mobile no.,
job type: student/teacher.
Figure 4. registration page
Module 3: authentication of client
Authentication is divided into two parts :
First factor: it is based on „something you know‟ i.e. username and password.
Figure 5. login panel
Second factor: It is based on „something you have‟ in which a user have to enter the mobile token
generated in their mobile phones by accessing multi-auth app displayed in figure(6).
144
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
Figure 6 : OTP panel
Multi-auth-app : this is an application run on users mobile phones. This application also have
various steps for authentication. That is why known as multi-step authentication. Fig(7) shows
various steps multi-auth-app.
Figure 7. multi-auth-app
Module 4. User interface for sharing data and permissions:
Figure(8) shows user profile which includes features of uploading data, add friends, search friends,
delete friends, permissions for viewing data- allow/ deny.
Figure 8. user‟s profile
145
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
Encryption and decryption data: the data uploaded to the cloud is in encrypted form using AES as
shown in figure(9) and decrypted while accessing by authenticated users shown in figure(10). Also
details of users information while login, registration and profile management are stored in encrypted
form using MD-5 on the cloud server shown in fig(11) and fig(12).
Encryption
figure 9. data uploaded on cloud
Decryption
Figure 10. Decryption
Figure 11 Login details in encrypted form
146
Divya Saraswat* , Dr. Pooja Tripathi
International Journal of Innovations & Advancement in Computer Science
IJIACS
ISSN 2347 – 8616
Volume 4, Special Issue
May 2015
Figure 12. profile management in encrypted form
VII.
CONCLUSION
A two factor authentication approach is employed for the authentication and authorization of the
client, which increase the confidentiality and integrity of the data. One time password to authenticate
users and MD5 hashing for hiding information. This model ensures security for whole cloud
computing structure. In this paper we propose different ways to securely and easy login to a cloud
service using OTPs with the user's mobile phone as an authentication device. AES encryption
technique is used for data storing security in cloud. With the authentication, registration and
encryption method proposed and implemented in this paper, all of those factors are accomplished.
Algorithms like AES, MD-5 and OTP with multi-auth app makes the model highly secure.
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Divya Saraswat* , Dr. Pooja Tripathi