q101/random_k4/random_2.md

International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013

Securing Software as a Service Model of Cloud
Computing: Issues and Solutions

Rashmi 1, Dr.G.Sahoo2, Dr.S.Mehfuz3

1,2Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India3Jamia Milia
Islamia,Delhi,India

ABSTRACT

Cloud computing, undoubtedly, has become the buzzword in the IT industry today. Looking at the potential
impact it has on numerous business applications as well as in our everyday life, it can certainly be said that
this disruptive technology is here to stay. Many of the features that make cloud computing attractive, have
not  just  challenged  the  existing  security  system,  but  have  also  revealed  new  security  issues.  This  paper
provides an insightful analysis of the existing status on cloud computing security issues based on a detailed
survey carried by the author. It also makes an attempt to describe the security challenges in Software as a
Service (SaaS) model of cloud computing and also endeavors to provide future security research directions.

KEY WORDS:

Cloud Computing, Software as a Service, Security Challenges

1.INTRODUCTION

A lot has been written and spoken about Cloud Computing technology, by  IT experts, industry
and  business  leaders  and  independent  experts.  While  some  believe  it  is  a  disruptive  trend
representing  the  next  stage  in  the  evolution  of  the  Internet,  others  believe  it  is  hype,  as  it  uses
earlier  established  computing  technologies.  So,  what  exactly  is  cloud  computing?  From  a  user
perspective,  cloud  computing  provides  a  means  for  acquiring computing  services  without  any
need  for  deep  understanding  of  the  underlying  technology  being  used.  From  an  organizational
perspective, cloud computing delivers services for consumer and business needs in a simplified
way,  providing  unbounded  scale  and  differentiated  quality  of  service  to  foster  rapid  innovation
and decision making. According to Gartner [1], cloud computing can be defined as ‘‘a style of
computing,  where  massively  scalable  IT- enabled  capabilities  are  delivered  ‘as  a  service’  to
external  customers  using  Internet  technologies.  According  to  the Seccombe  [2] and  National
Institute  of  Standards  &  Technology [3],  guidelines  for  cloud  computing,  it  has  four  different
deployment  models  namely  private,  community,  public  and  hybrid  as  well  as  three different
delivery models that are utilized within a particular deployment model. These delivery models are
the  SaaS  (Software  as  a  Service),  PaaS  (Platform  as  a  Service)  and  IaaS  (Infrastructure  as  a
Service). These models form the core of the cloud and they exhibit certain key characteristics like
on  demand  self-service,  broad  network  access,  resource  pooling,  measured  service  and  rapid
elasticity. Our main area of concern in this paper is the Software as a service (SaaS). model This
best-known branch of cloud computing , is a delivery model in which applications are hosted and
managed  in  a  service provider's  datacenter, paid  for  on  a  subscription basis  and  accessed  via  a
browser over  an  internet  connection. It  basically  deals  with  licensing  of  an  application  to  the
customers for use as a service on demand. One good example of SaaS is the Salesforce.com CRM
application.

DOI : 10.5121/ijccsa.2013.3401

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International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013

This paper focuses on the issues related to the service delivery model of cloud computing. The
paper describes the various security issues of cloud computing with respect to its service delivery
model SaaS. The organization of the paper is as follows: Section 2 describes the security issues
that  are posed by  the  Software  as a  Service  (SaaS) delivery  model.  Section 3 lists  some of  the
current solutions  which  partly  target  the  security  challenges  posed  by  the  SaaS.  Section  4
provides conclusions derived out of the survey undertaken.

2.SECURITY ISSUES IN SAAS

In Software as a Service (SaaS) model, the client has to depend on the service provider for proper
security measures. The provider must ensure that the multiple users don’t get to see each other’s
data. So, it becomes important to the user to ensure that right security measures are in place and
also  difficult  to  get  an  assurance  that  the  application  will  be  available  when needed  [4].  While
using  SaaS  model,  the  cloud  customer  will,  by  definition,  be  substituting  new  software
applications  for  old  ones.  Therefore,  the  focus  is  not  upon  portability  of  applications,  but  on
preserving  or  enhancing the  security  functionality  provided  by  the  legacy  application  and
achieving a successful data migration [2] The SaaS software vendor may host the application on
his  own  private  server  or  deploy  it  on  a  cloud  computing  infrastructure  service  provided  by  a
third-party provider (e.g. Amazon, Google,  etc.).  The use of  cloud  computing  coupled with  the
‘pay-as-you-go’  approach  helps  the  application  service  provider  reduce  the  investment  in
infrastructure services and enables it to concentrate on providing better services to the customers.
Enterprises  today  view  data  and  business  transactions  as  strategic  and  guard  them  with  access
control  and  compliance  policies.  However,  in  the  SaaS  model,  enterprise  data  is  stored  at  the
SaaS  provider’s  data  center,  along  with  the  data  of  other  enterprises.  Moreover,  if  the  SaaS
provider is leveraging a public cloud computing service, the enterprise data might be stored along
with  the  data  of  other  unrelated  SaaS  applications.  The  cloud  provider  might,  additionally,
replicate  the data  at  multiple  locations  across  countries  for  the  purposes  of  maintaining  high
availability. Most enterprises are familiar with the traditional on- promise model, where the data
continues  to  reside  within  the  enterprise  boundary,  subject  to  their  policies.  Cloud  computing
traditional
providers  need
communication  systems.  At  the  same  time,  they  also  have  to  deal  with  other  issues  inherently
introduced  by  the  cloud  computing  paradigm  itself.  In  the  following  section,  the  SaaS  security
issues have been categorized as traditional and new cloud specific security challenges, for sake of
convenience. Figure 1 shows the various security issues in SaaS model which are discussed in the
paper.

the  common  security  challenges  being  faced  by

to  solve

2.1

Traditional Security Challenges

Although the security concerns in traditional communication systems also apply to the cloud, the
use  of  cloud  computing  introduces  new  attack  vectors  that  will  make  attacks  either  possible  or
simply  easier  to  carry  out.  Some  of  the  traditional  security  issues  which  also  affect  the  SaaS
model have been described below:

Authentication and authorization

The  authentication  and  authorization  applications  for  enterprise  environments  may  need  to  be
changed,  to  work  with  a  safe  cloud  environment.  Forensics  tasks  may  become  much  more
difficult since the investigators may not be able to access system hardware physically. The design
proposed  by  Pratap  Murukutla [5] allows  user  to  use  a  single  set  of  credentials.  They  have
proposed a solution with de-facto standards of open authorization in which there is a trust party
auditor which maintains all the credentials and cloud provider can uniquely distinguish one user
from  other.  The  model  proposed  in  the  literature [6] verifies  user  authenticity  using  two-step

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International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013

verification,  which  is  based  on  password,  smartcard  and  out  of  band  (i.e.  strong  two  factors)
authentication. In addition, the scheme also provides mutual authentication, identity management,
session key establishment, user privacy and security against many popular attacks; however the
formal security proofing hasn’t yet been formalized.

Availability

The availability ensures the reliable and timely access to cloud data or cloud computing resources
by  the  appropriate  personnel.  The  availability  of  cloud  service  providers  is  also  a  big  concern,
since if the cloud service is disrupted; it affects more customers than in the traditional model. For
instance, the recent disruption of the Amazon cloud service in the year 2011, took down a number
of websites including Reddit, Foursquare, and Quora.The SaaS application providers are required
to ensure that the systems are running properly when needed and enterprises are provided with
services  around  the  clock.  This  involves  making  architectural  changes  at  the  application  and
infrastructural  levels  to  add  scalability  and  high  availability.  Resiliency  to  hardware/software
failures, as well as to denial of service attacks, needs to be built from the ground up within the
application.  At  the  same  time,  an  appropriate  action  plan  for  business  continuity  and  Disaster
Recovery (DR) needs to be considered for any exigencies as per the guidance provided by [2].
This is essential to ensure the safety of the enterprise data while maintaining minimal downtime
for  the  enterprises.  With  Amazon [7] for  instance,  the  Amazon  Web  Services  (AWS)  API  end
points are hosted on the same Internet-scale, world-class infrastructure that supports the Amazon
retail  site.  Standard  Distributed  Denial  of  Service  (DDoS)  mitigation  techniques  such  as
synchronous cookies and connection limiting are used. To further mitigate the effect to potential
DDoS attacks, Amazon maintains internal bandwidth that exceeds its provider-supplied Internet
bandwidth.

Data confidentiality

Confidentiality refers to the prevention of intentional or unintentional unauthorized disclosure of
information. Confidentiality in cloud system is related to the areas of intellectual property rights,
covert  channels,  traffic  analysis,  encryption,  and  inference [10].  Cloud  computing  involves  the
sharing or storage of information on remote servers owned or operated by others, while accessing
through the Internet or any other connections. Cloud computing services exist in many variations,
including data storage sites, video sites, tax preparation sites, personal health record websites and
many  more.  The  entire  contents  of  a  user’s  storage  device  may  be  stored  with  a  single  cloud
provider  or  with  multiple  cloud  providers.  Whenever  an  individual,  a  business,  a  government
agency, or any other entity shares information in the cloud, privacy or confidentiality questions
arise.

Virtual Machine Security

Although the global adoption of virtualization is a relatively a recent phenomena, threats to the
virtualized  infrastructure  are  evolving  just  as  quickly [8].  The  hypervisor  and  virtual  machines
used  in  cloud  providers  may  also  have  vulnerabilities,  as  exemplified  by [14].  Such
vulnerabilities  represent  an  even  more  serious  problem  in  multi-tenant  environments,  where
compromise of even a single virtual machine can affect all users on the same physical server.

Virtualization  is  one  of  the  main  components  of  a  cloud.  But  this  poses  major  security  risks.
Ensuring  that  different  instances  running  on  the  same  physical  machine  are  isolated  from  each
other is a major task of virtualization which is not met completely in today’s scenario. The other issue
is  the  control  of  administrator  on  host  and  guest  operating  systems.  Current  Virtual  Machine
Monitor (VMMs do not offer perfect isolation. Many bugs have been found in all popular VMMs
that allow escaping from VM. Virtual machine monitor should be ‘root secure’, meaning that no

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International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013
International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013
International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013

privilege  within  the  virtualized  guest  environment  permits  interference  with  the  host  system.
privilege  within  the  virtualized  guest  environment  permits  interference  with  the  host  system.
privilege  within  the  virtualized  guest  environment  permits  interference  with  the  host  system.
Some  vulnerability  has  been  found  in  all  virtualization  software  which  can  be  exploited  by
Some  vulnerability  has  been  found  in  all  virtualization  software  which  can  be  exploited  by
Some  vulnerability  has  been  found  in  all  virtualization  software  which  can  be  exploited  by
malicious, local users to bypass certain security restrictions or gain privileges. For example, the
malicious, local users to bypass certain security restrictions or gain privileges. For example, the
malicious, local users to bypass certain security restrictions or gain privileges. For example, the
vulnerability of Microsoft Virtual PC and Microsoft Virtual Server could allow a guest operating
vulnerability of Microsoft Virtual PC and Microsoft Virtual Server could allow a guest operating
vulnerability of Microsoft Virtual PC and Microsoft Virtual Server could allow a guest operating
system user to run code on the host or another guest operating system. Vulnerability in Virtual PC
system user to run code on the host or another guest operating system. Vulnerability in Virtual PC
system user to run code on the host or another guest operating system. Vulnerability in Virtual PC
and Virtual Server could allow elevation of privilege. Cloud providers, therefore, might need to
and Virtual Server could allow elevation of privilege. Cloud providers, therefore, might need to
and Virtual Server could allow elevation of privilege. Cloud providers, therefore, might need to
reconsider traditional security concerns from different angles.
reconsider traditional security concerns from different angles.
reconsider traditional security concerns from different angles.

Figure 1: Security Issues in SaaS
Figure 1: Security Issues in SaaS
Figure 1: Security Issues in SaaS

2.2
2.2
2.2

Cloud Specific Security Challenges
Cloud Specific Security Challenges
Cloud Specific Security Challenges

Information Security
Information Security
Information Security

]
]
]
In  a  traditional  on-premise  application  deployment  model,  the  sensitive  data  of  each  enterprise
In  a  traditional  on-premise  application  deployment  model,  the  sensitive  data  of  each  enterprise
In  a  traditional  on-premise  application  deployment  model,  the  sensitive  data  of  each  enterprise
continues  to  reside  within  the  enterprise  boundary  and  is  subject  to  its  physical,  logical  and
continues  to  reside  within  the  enterprise  boundary  and  is  subject  to  its  physical,  logical  and
continues  to  reside  within  the  enterprise  boundary  and  is  subject  to  its  physical,  logical  and
personnel security and access control policies. However, in the SaaS model, the enterprise data is
personnel security and access control policies. However, in the SaaS model, the enterprise data is
personnel security and access control policies. However, in the SaaS model, the enterprise data is
stored outside the enterprise boundary, at  the SaaS vendor end. Consequently, the SaaS vendor
stored outside the enterprise boundary, at  the SaaS vendor end. Consequently, the SaaS vendor
stored outside the enterprise boundary, at  the SaaS vendor end. Consequently, the SaaS vendor
must adopt additional security checks to ensure data security and prevent breaches due to security
must adopt additional security checks to ensure data security and prevent breaches due to security
must adopt additional security checks to ensure data security and prevent breaches due to security
vulnerabilities in the application or through malicious employees. This involves the use of strong
vulnerabilities in the application or through malicious employees. This involves the use of strong
vulnerabilities in the application or through malicious employees. This involves the use of strong
encryption techniques for data security and fine-grained authorization to control access to data.
encryption techniques for data security and fine-grained authorization to control access to data.
encryption techniques for data security and fine-grained authorization to control access to data.

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International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013

In cloud vendors such as Amazon, the Elastic Compute Cloud (EC2) administrators do not have
access  to  customer  instances  and  cannot  log  into  the  Guest  OS.  EC2  Administrators  with  a
business  need  are  required  to  use  their  individual  cryptographically  Strong  Secure  Shell  (SSH)
keys to gain access to a host [8]. All such accesses are logged and routinely audited. While the
data  at  rest  in  Simple  Storage  Service  (S3)  is  not  encrypted  by  default,  users  can  encrypt  their
data  before  it  is  uploaded  to  Amazon  S3,  so  that  it  is  not  accessed  or  tampered  with  by  any
unauthorized  party.  Malicious  users  can  exploit  weaknesses  in  the  data  security  model  to  gain
unauthorized access to data.

Network  Security

In  a  SaaS  deployment  model,  sensitive  data  is  obtained  from  the  enterprises,  processed  by  the
SaaS application and stored at the SaaS vendor end. All data flow over the network needs to be
secured  in  order  to  prevent  leakage  of  sensitive  information.  This involves  the  use  of  strong
network traffic encryption techniques such as Secure Socket Layer (SSL) and the Transport Layer
Security (TLS) for security.

In  case  of  Amazon  Web  Services  (AWS),  the  network  layer  provides  significant  protection
against  traditional  network  security  issues,  such  as  MITM  (Man-In-The-Middle)  attacks,  IP
spoofing, port scanning, packet sniffing, etc. For maximum security, Amazon S3 is accessible via
SSL  encrypted  endpoints.  The  encrypted  end  points  are  accessible  from  both  the  Internet  and
from within AmazonEC2, ensuring that data is transferred securely both within AWS and to and
from sources outside of AWS [9]. However, malicious users can exploit weaknesses in network
security configuration to sniff network packets.

Resource  Localty

In  a  SaaS  model  of  a  cloud  environment,  the  end-users  use  the  services  provided  by  the  cloud
providers without knowing exactly where the resources for such services are located, possibly in
other  legislative  domains.  This  poses  a  potential  problem  when  disputes  happen,  which  is
sometimes  beyond  the  control  of  cloud  providers.  Due  to  compliance  and  data  privacy  laws  in
various  countries,  locality  of data  is of utmost  importance  in  much enterprise architecture [15].
The European Union has issued a Directive 95/46/EC to protect the user privacy at all costs [16].
The directive prohibits  transfers of personal data  to  countries which do not  ensure  an adequate
level  of  protection.  For  example,  the  recent  Dropbox  users  have  to  agree  to  the  ‘‘Terms  of
Service’’ which grant the providers the right to disclose user information in compliance with laws
and law enforcement requests [17].  In addition to the issue of local laws, there’s also the question
of  under  whose  jurisdiction  the  data  falls,  when  an  investigation occurs.  A  secure  SaaS  model
must  be  capable  of  providing  reliability  to  the  customer  on  the  location  of  the  data  of  the
consumer.

Cloud standards

To  achieve  interoperability  among  clouds  and  to  increase  their  stability  and  security,  cloud
standards are needed across different standard developing organizations. For example, the current
storage services by a cloud provider may be incompatible with those of other provider. In order to
keep  their  customers,  cloud  providers  may  introduce  so  called  ‘‘sticky  services’’  which  create
difficulty for the users if they want to migrate from one provider to the other, e.g., Amazon’s S3
is incompatible with IBM’s Blue Cloud or Google storage. There are currently a large number of
standards bodies with different interests, e.g. IEEE Cloud Computing Standard Study Group [18],
ITU  Cloud  Computing  Focus  Group [19],  Cloud  Security  Alliance  (CSA),  Distributed
Management Task Force [20], Storage Networking Industry Association [21], Open Grid Forum
[22],  Open  Cloud  Consortium  [23] and  Organization  for  the  Advancement  of  Structured

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Information  Standards  [24],  and  so  forth.  To  promote  the  wide  use  of  cloud  computing,  these
standards  bodies  need  to  sit  down  and  work  together  to  establish  common  standards.  Possible
‘‘Inter-cloud’’  standards  in  the following domains  are  needed  to  increase  cloud interoperability
and free data movement among clouds:

– Network architecture,
– Data format,
– Metering and billing,
– Quality of Service,
– Resource provisioning,
– Security, identity management and privacy.

As stated, there are many general computing standards that may be reused in the cloud, but for
the  moment,  there  are  to  our  knowledge  no  dedicated  cloud  standards.  This  may  add  to  the
confusion for cloud users [25], and is something which must be addressed in the future.

Data Segregation

Multi-tenancy  is  one  of  the  major  characteristics  of  cloud  computing.  As  a  result  of  multi-
tenancy,  multiple  users  can  store  their  data  using  the  applications  provided  by  SaaS.  In  such  a
situation, data of various users will reside at the same location. Intrusion of data of one user by
another  becomes  possible  in  this  environment.  This  intrusion  can be  done  either  by  hacking
through the loop holes in the application or by injecting client code into the SaaS system. A client
can  write  a  masked  code  and  inject  into  the  application.  If  the  application  executes  this  code
without  verification,  then  there is a high potential  of intrusion  into other’s data.  A  SaaS  model
should therefore ensure a clear boundary for each user’s data. The boundary must be ensured not
only  at  the  physical  level  but  also  at  the  application  level.  The  service  should  be  intelligent
enough  to  segregate  the  data  from  different  users.  A  malicious  user  can  use  application
vulnerabilities to hand- craft parameters that bypass security checks and access sensitive data of
other tenants.

Data Access

Data access issue is mainly related to security policies provided to the users while accessing the
data. In a typical scenario, a small business organization can use a cloud provided by some other
provider  for  carrying  out  its  business  processes.  This  organization  will  have  its  own  security
policies based on which each employee can have access to a particular set of data. The security
policies may entitle some considerations, wherein, some of the employees are not given access to
certain  amount  of  data [26].  These  security  policies  must  be  adhered  by  the  cloud  to  avoid
intrusion  of  data  by  unauthorized  users [27].The  SaaS  model  must  be  flexible  enough  to
incorporate the specific policies put forward by the organization. The model must also be able to
provide  organizational  boundary  within  the  cloud  because  multiple  organization  will  be
deploying their business processes within a single cloud environment.

Web application security

SaaS is software deployed over the internet and/or is deployed to run behind a firewall in local
area network or personal computer. The key characteristics include Network-based access to, and
management of, commercially available software and managing activities from central locations
rather  than  at  each  customer’s  site,  enabling  customers  to  access  application  remotely  via  the
Web.  SaaS  application  development  may  use  various  types  of  software  components  and
frameworks. These tools can reduce time-to-market and the cost of converting a traditional on-
premise  software  product  or  building  and  deploying  a  new  SaaS  solution.  Examples  include

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components for subscription management, grid computing software, web application frameworks
and  complete  SaaS  platform  products.  One  of  the  ‘‘must-have’’  requirements  for  a  SaaS
application  is  that  it  has  to  be  used  and  managed  over  the  web [28].  The  software  which  is
provided  as  a  service  resides  in  the  cloud  without  tying  up  with  the  actual  users.  This  allows
improvising the software without inconveniencing the user. Security holes in the web applications
thus  create  a  vulnerability to  the  SaaS application  [29].  In  this  scenario,  the  vulnerability  can
potentially have detrimental impact on all of the customers using the cloud. The challenge with
SaaS  security  is  not  any  different  than  with  that  of  any  other  web  application  technology.
However  one  of  the  problems  is  that  traditional  network  security  solutions  such  as  network
firewalls,  network  intrusion  detection  and  prevention  systems  (IDS  &  IPS),  do  not  adequately
address  this  problem.  Web  applications  introduce  new  security  risks  that  cannot  effectively  be
defended against at the network level, and do require application level defenses. The Open Web
Application  Security  Project  [30] has  provided  the  ten  most  critical  web  applications  security
threats.

Data breaches

Since  data  from  various  users  and  business  organizations  lie  together  in  a  cloud  environment,
breaching  into  the  cloud  environment will  potentially  attack  the data of  all  the users.  Thus,  the
cloud becomes a high value target [31]. In the Verizon Business breach report blog it has been
stated  that  external  criminals  pose  the  greatest  threat  (73 percent), but  achieve the  least  impact
(30,000 compromised records), resulting in a Virtualization vulnerability [32].

Backup

The  traditional  backup  methods  used  with  earlier applications  and  data  centers  that  were
primarily  designed  for  web  and  consumer  applications,  are  not  optimally  designed  for  the
applications running in the cloud. The SaaS vendor needs to ensure that all sensitive enterprise
data is regularly backed up to facilitate quick recovery in case of disasters. Also the use of strong
encryption schemes to protect the backup data is recommended to prevent accidental leakage of
sensitive information. In the case of cloud vendors such as Amazon, the data at rest in S3 is not
encrypted by default. The users need to separately encrypt their data and backups so that it cannot
be accessed or tampered with by unauthorized parties.

Identity management and sign-on process

Identity management (IdM) or ID management is an area that deals with identifying individuals
in a system and controlling the access to the resources in that system by placing restrictions on
the established identities. This area is considered as one of the biggest challenges in information
security.  When a  SaaS  provider  has  to  know  how  to  control  who  has  access  to  what  systems
within the enterprise it becomes all the more challenging task. In such scenarios the provisioning
and de-provisioning of the users in the cloud becomes very crucial.

3.CURRENT SECURITY SOLUTIONS

There  are  several  research  works  happening  in  the  area  of  cloud  security.  Several  groups  and
organization  are  interested  in  developing  security  solutions  and  standards  for  the  cloud.  The
Cloud  Security  Alliance  (CSA)  is  gathering  solution  providers,  non- profits  and  individuals  to
enter into discussion about the current and future best practices for information assurance in the
cloud [11]. The Cloud Standards website collects and coordinates information about cloud-related
standards  under  development  by  the  groups.  The  Open  Web  Application  Security  Project
(OWASP) maintains list of top vulnerabilities to cloud-based or SaaS models which is updated as
the  threat  landscape changes  [30].  The  Open  Grid  Forum  publishes  documents  to  containing

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security  and  infrastructural  specifications  and  information  for  grid  computing  developers  and
researchers [22].  The  best  security  solution  for  SaaS  applications  is  to  develop  a  development
framework that has tough security architecture. Tsai W [33], put forth a four-tier framework for
web-based  development  that  though  seems  interesting,  only  implies  a  security  facet  in  the
process. In  his  work,  Berre [34] has  suggested  a  road  map  towards  cloud-centric  development,
and the X10 language is one of the ways to achieve better use of cloud capabilities of massive
parallel  processing  and concurrency  [35].Another  approach  is  resource  isolation  to  ensure
security  of  data  during  processing,  by  isolating  the  processor  caches  in  virtual  machines,  and
isolating  those  virtual  caches  from  the  hypervisor  cache [36].  One  simple  solution,  for  UK
businesses is to simply use in-house ‘‘private clouds’’ [37] .Pearson highlighted that the current
lack of transparency is preventing many users from reaping the true benefits of the cloud [38].

For  Identity  and  access  management  in  the SaaS,[12] has  issued  an  Identity  and  Access
Management Guidance which provides a list of recommended best practices to assure identities
and secure access management. Resource Locality and Data Segregation are the two key security
challenges  on  which  not  much  information  is  available  in  the  existing  literature,  which
necessitates that this can be further taken up for research.

Table 1: Current solutions available for securing SaaS

S.No. Security Areas
Authentication
1
authorization

and

2
3
4

5

6

7

8

9

10
11

12

Availability
Data confidentiality
Virtual
Security

Machine

Information  Security

Network  Security

Cloud standards

Data Access

application

Web
security
Data breaches
Backup

Identity
and sign-on process

management

virtual

distributed

Current /Possible Solutions
• Open Authorization [5]
• Two Factor Authentication [6]
• OAuth [39]
• Data Dispersion[8]
• Attribute based Proxy Re-Encryption [40]
• Reconfigurable
machine[41]
• Survey on Virtual machine Security [42]
• Information Security  Risk  Management
Framework
[43]
• Network Security for virtual machines [44]
• Network Security Sandbox[45]
• IEEE  Cloud  Computing  Standard  Study
Group [18]
• ITU Cloud Computing Focus Group [19],
• Cloud Security Alliance (CSA)
• Multi-user access policies [46].
• Data Access Management [47].
• Web Application Scanners[48]

• Agentless  Method  for  data  Backup  and
Recovery [49]
• CSA’s  Identity  and  Access  Management
Guidance [12]

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International Journal on Cloud Computing: Services and Architecture (IJCCSA) ,Vol.3, No.4, August 2013

4.CONCLUSION

Though  there  are  numerous  advantages  in  using  a  cloud-based  system,  there  are  yet  many
practical  issues  which  have  to  be  sorted.  Cloud  computing  is  a  disruptive  technology  with
profound implications not only for Internet services but also for the IT sector as a whole. Still,
several outstanding issues exist, particularly related to service-level agreements (SLA), security
and privacy, and power efficiency. As described in the paper, currently security has lot of loose
ends  which scares  away  several potential  users. Until  a  proper  security  module  is  not  in place,
potential  users  will  not  be  able  to  leverage  the  true  benefits  of  this  technology.  This  security
module should cater to all the issues arising from all directions of the cloud. Every element in the
cloud  should  be  analyzed  at  both  the  macro  and  micro  level  and  subsequently  an  integrated
solution must be designed and deployed in the cloud to attract and retain the potential consumers.
Until  then,  cloud  environment  will  remain  cloudy.  In  a  cloud,  where there  are  heterogeneous
systems having a variation in their asset value, a single security system would be too costly for
certain applications and if there is less security then the vulnerability factor of some applications
like  financial  and  military  applications  will  shoot  up.  On  the  other  side,  if  the  cloud  has  a
common security methodology in place, it will be a high value asset target for hackers because of
the fact that hacking the security system will make the entire cloud  vulnerable to attack.

In this  paper  an  overview  of  cloud  computing  service  delivery  model,  SaaS  along  with  the
security  challenges  ,  including  both  the  traditional  and  cloud  specific  security  challenges
,associated  with  the  model  has  been  presented  A  number  of  new  challenges  that is    inherently
connected  to  the  new  cloud  paradigm  has  also  been  deliberated  in  the  paper.  As  secure  data
storage in cloud environment is a significant concern which prevents many users from using the
cloud, a practical solution to provide security and privacy for user data, when it is located in a
public  cloud,  was  also  discussed  in  this  paper.  The  need  for  further  work  on  various  security
mechanisms has also been highlighted, in order to provide transparent services that can be trusted
by all users.

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Authors

Rashmi
Rashmi is a researcher at Birla Institute of Technology. Her current research focus is on Cloud Computing
and  securing  Cloud  environments.  She  holds  her  B.E.  degree  in  Information  Technology  from  Pune
University,  India in  2005 and M.Tech. In  Computer Science in  2008.She was awarded “Gold  Medal” for
her  overall academic excellence. She  has also  worked as a Software Engineer in reputed IT firms  before
joining academic career. She can be contacted at: rashmirrai@gmail.com

Dr.G.Sahoo
G. Sahoo received his MSc in Mathematics from Utkal University in the year 1980 and PhD in the Area of
Computational Mathematics from Indian Institute of Technology, Kharagpur in the year 1987. He has been
associated  with  Birla  Institute  of  Technology,  Mesra,  Ranchi, India  since  1988,  and  currently,  he  is
working  as  a  Professor  and  Head in  the  Department  of  Information  Technology.  His  research interest
includes  Theoretical  Computer  Science,  Parallel  and Distributed  Computing,  Cloud  Computing,
Evolutionary Computing, Information Security, Image Processing and Pattern Recognition.

Dr.Shabana Mehfuz
Shabana Mehfuz received her B.Tech degree in Electrical Engineering from Jamia Millia Islamia, India in
1996  and  M.Tech  degree  in  Computer  technology  from  IIT  Delhi  in  2003  and  PhD  in  Computer
Engineering  from  Jamia  Millia  Islamia  in  2008.  She  is  currently  working  as  Associate  Professor  at  the
Department  of  Electrical  Engineering.  Her  research  interest  includes  Computational  Intelligence  and
Computer Networks.

11