SlideShare a Scribd company logo
PUBLIC AUDITING
FOR SECURE CLOUD STORAGE
Anand K Menon[MTALECS004 ]
Bharath Chandran Nair[MTALECS015]
Godwin C Antony[MTALECS025]
Eighth semester B.Tech CSE, Department of Computer Science,
Met’s School of Engineering,Mala,
Under the Guidance of
Miss.Asha S
Assistant Professor, Dept. of CSE,
Met’s School of Engineering,Mala
OUTLINE OF THE PRESENTATION
o OBJECTIVE
o INTRODUCTION
o LITERATURE SURVEY
o EXISTING METHOD
o PROBLEM DESCRIPTION
o BLOCK DIAGRAM
o PROPOSED METHOD
o APPLICATIONS
o RESULT AND DISCUSSION OF BASE PAPER
o EXECUTION TOOLS
o CONCLUSION
o REFERENCES
OBJECTIVE
 The objective of the system is to develop a system
that would enable the cloud users to have control
over their data so that they can ensure that their
data is secured and not corrupted.
 It provides security to the users data by encrypting
the data and splitting up the file into small blocks for
storage.
 Auditing the cloud storage without demanding a
local copy of data enables more efficiency.
INTRODUCTION
 Cloud computing customers do not own a physical
infrastructure; rather they rent the usage from a third
party provider.
 They consume resources as a service and pay only for
resources that they use.
 Cloud computing comes in three forms: public clouds,
private clouds, and hybrids clouds.
 Public clouds offer the greatest level of efficiency in
shared resources but are more vulnerable.
 Private clouds offer the greatest level of security and
control, but they require the company to still purchase
and maintain all the software and infrastructure.
 Hybrid cloud includes both public and private
options.The downside is that we have to keep track of
multiple different security platforms.
 Cloud computing provides on demand self
services,location independent resource
pooling,rapid resource elasticity,usage based
pricing etc..
 Challenge faced is security threats towards users
outsourced data.
 Here the correctness of user data in the cloud is put
at risk.
 CSP might reclaim storage for monetary reasons by
discarding rarely accesed data or even hiding data
corruption due to server hacks over byzantine
failures.
LITERATURE REVIEW
SL
.N
O
AUTHOR YEAR TITLE DESCRIPTION
1 P. Mell and T.
Grance
June 2009 DraftNISTworking
definitionofcloud
computing
Subscribers should identify the specific resources that are
suitable for migrating data into and out of clouds.
Resources could be services such as: (1) email, (2)
data repositories such as shared documents, or (3) systems that run in
virtualized environments.
2 M. Arrington December
2006
Gmail disaster: Reports
of mass email
deletions
Cloud Computing provides convenient on demand network access to
a shared pool of configurable computing
resources that can be rapidly deployed with the great efficiency and
minimal management overhead.
3 J. Kincaid December
2006.
MediaMax/TheLinkup
Closes Its Doors
To achieve the assurances of cloud data
integrity and availability and enforce the quality of
dependable cloud storage service for users, To
propose an effective and flexible distributed
scheme with explicit dynamic data support,
including block update, delete, and append.
LITERATURE REVIEW
S
L
.
N
O
AUTHOR YEAR TITLE DESCRIPTION
4 M.A.Shah,R.Swamina
than, and M. Baker
Oct.
2008
Privacy-preserving audit
and extraction of digital
contents
A growing number of online services, such as Google, Yahoo!,
and Amazon, are starting to charge users for their storage.
Customers often use these services to store valuable data such as
email, family photos and videos, and disk backups. Today, a
customer must entirely trust such external services to maintain
the integrity of hosted data and return it intact.
5 Q. Wang, C. Wang, J.
Li, K. Ren, and W.
Lou
Sep.
2009
Enabling publicverifiability
and data dynamics for
storage security in cloud
computing
Cloud Computing has been envisioned as the next-generation
architecture of IT Enterprise. It moves the application software
and databases to the centralized large data centers, where the
management of the data and services may not be fully
trustworthy.
6 G. Ateniese, S.
Kamara, and J. Katz
2009 Proofs of storage
fromhomomorphic
identification protocols
Proofs of storage (PoS) are interactive protocols allowing a client
to verify that a server faithfully stores a file. Previous work has
shown that proofs of storage can be constructed from any
homomorphic linear authenticator (HLA). The latter, roughly
speaking, are signature/message authentication schemes where
`tags' on multiple messages can be homomorphically combined
to yield a `tag' on any linear combination of these messages.
8
BASIC SCHEME 1
MAC
key
File block
code
Message Authentication Code (MAC)
Block 1 Block nBlock 2 …
File is divided into blocks
Cloud
user
TPA
Block 1 Block n…Block 2
code 1 code n…code 2
-User computes the MAC of every file block
-Transfers the file blocks & codes to cloud
-Shares the key with TPA
Audit
-TPA demands a random number of
blocks and their code from CSP
-TPA uses the key to verify the
correctness of the file blocks
Drawbacks: -The audit demands retrieval of user’s data; this is not privacy-preserving
-Communication and computation complexity are linear with the sample size
EXISTING METHOD
9
BASIC SCHEME 2
Block 1 Block n…Block 2
code 1 code n…code 2
code 1 code n…code 2
code 1 code n…code 2
Key 1
Key 2
Key s
…
user
Cloud
TPA
Block 1 Block m…Block 2
Setup
-User uses s keys and computes the MAC for blocks
-User shares the keys and MACs with TPA
Audit
-TPA gives a key (one of the s keys) to CSP and requests MACs for the blocks
-TPA compares with the MACs at the TPA
-Improvement from Scheme 1: TPA doesn’t see the data, preserves privacy
-Drawback: a key can be used once.
-The TPA has to keep a state; remembering which key has been used
-Schemes 1 & 2 are good for static data (data doesn’t change at the cloud)
PROBLEM DESCRIPTION
 Audit cloud storage demanding local copy of data.
 Violates the privacy-preserving guarantee.
 Large communication overhead and time delay.
 Band-width available between the TPA and the
cloud server is limited.
 Auditor can modify user data.
 Copy of user data on auditing side.
 No data control on user side.
 The number of times a particular data file can be
audited is limited by the number of secret key.
BLOCK DIAGRAM
U: cloud user has a large amount of data files to store in the cloud
CS: cloud server which is managed by the CSP and has significant
data storage and computing power (CS and CSP are the same in
this paper)
TPA: third party auditor has expertise and capabilities that U and
CSP don’t have. TPA is trusted to assess the CSP’s storage security
upon request from U
Setup & audit phases of public auditing scheme.
 Consists of four algorithms (KeyGen, SigGen,
GenProof, VerifyProof)
 KeyGen: key generation algorithm that is run by
the user
 SigGen: used by the user to generate verification
metadata, which may consist of MAC, signatures or
other information used for auditing
 GenProof: run by the cloud server to generate a
proof of data storage correctness
 VerifyProof: run by the TPA to audit the proof
from the cloud server
14
user KeyGen
Public key (sk)&
Secret key (pk)
Setup
SigGenuser
sk
Block 1 Block 2 Block n…
σ1 …σ2 σn
Block 1 Block n…Block 2
σ1 … σnσ2
1- User generates public
and secret parameters
2- A code is generated for
each file block
3- The file blocks and their codes
are transmitted to the cloud
Audit
-TPA sends a challenge
message to CSP
-It contains the position
of the blocks that will be
checked in this audit
GenProofCSP
Selected blocks in challenge
Aggregate authenticator
-CSP also makes a linear combination
of selected blocks and applies a
mask. Separate PRF key for each
auditing.
-CSP send aggregate authenticator &
masked combination of blocks to TPA
VerifyProofTPA
Masked linear combination of requested blocks
Aggregate authenticator
Compare the obtained Aggregate
authenticator to the one received from
CSP
PROPOSED METHOD
 Public auditing scheme which provides a complete
outsourcing solution of data– not only the data
itself, but also its integrity checking
 System consist of client and server side application
and website.
 Effectively audit cloud storage without demanding
local copy of data.
 Extensive security and performance analysis shows
provably secure and highly efficient.
 Data conrtol in the hands of users only.
APPLICATIONS
 Used in applications that require public auditing.
 Can be used for batch auditing.
 Application that ensures storage correctness.
SEQUENCE DIAGRAMS
Login Process
Uploading a file
 Viewing File
 Checking the Security Status
DFD
CLIENT MODULE:
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
TPA MODULE (THIRD PARTY AUDITOR):
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
CSP MODULE (CLOUD SERVICE PROVIDER):
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
DISCUSSION OF BASE PAPER
Objective of the Project
 The objective of the system is to develop a system
that would enable the cloud users to have control
over their data so that they can ensure that their
data is secured and not corrupted.
Scope of the Project
 “ Trusted Cloud Services” provides a security
solution to the cloud users. It ensures that the data
of the users that have been stored in a remote
server is secured and controlled.
Constraints
 Only the registered users will be authorized to use the
service.
 A trustworthy TPA is required to audit the storage.
Assumptions and dependencies
 The project will not change in scope
 The resources identified will be available upon request
 Approved funding will be available upon request
 Only the registered users can access the Website
 Roles and tasks are predefined.
EXECUTION TOOLS
Hardware Requirements
 Intel Pentium dual core processor or above
 1 GB RAM
 200 GB HDD
 Other standard peripherals
Software Requirements
 Operating system : windows XP
 Tool: Netbeans IDE 6.1
 Programming Package : Jdk.5.0
 Database :MySQL
 Server :Glassfish v2
CONCLUSION
 The aim of the project is to develop a system that
would enable the cloud users to have control over
their data so that they can ensure that their data is
secured .
 They can know whether there is any data loss or
corruption by logging into the website.
 TPA would not learn any knowledge about the
data content stored on the cloud server during the
efficient auditing process.
 TPA can perform multiple auditing tasks in a batch
manner for better efficiency.
 Schemes are provably secure and highly efficient.
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
PUBLIC AUDITING 	             FOR SECURE CLOUD STORAGE
REFERENCE
 P. Mell and T. Grance, “Draft NIST working definition of cloud
computing,” Referenced on June. 3rd, 2009 Online at
http://csrc.nist.gov/groups/SNS/cloud-computing/index.
html, 2009.
 M. Armbrust, A. Fox, R. Griffith, A. D. Joseph, R. H. Katz,
A. Konwinski, G. Lee, D. A. Patterson, A. Rabkin, I. Stoica,
and M. Zaharia, “Above the clouds: A berkeley view of cloud
computing,” University of California, Berkeley, Tech.
 M. Arrington, “Gmail disaster: Reports of mass email deletions,”
Online at http://www.techcrunch.com/2006/12/28/gmail-
disasterreports-of-mass-email-deletions/,December 2006.
 J. Kincaid, “MediaMax/TheLinkup Closes Its Doors,” Online at
http://www.techcrunch.com/2008/07/10/ mediamaxthelinkup-closes-
its-doors/, July 2008.
 Amazon.com, “Amazon s3 availability event: July 20, 2008,” Online
at http://status.aws.amazon.com/s3-20080720.html,2008.
 S. Wilson, “Appengine outage,” Online at http://www.cio-
weblog.com/50226711/appengine outage.php, June 2008.
 B. Krebs, “Payment Processor Breach May Be Largest Ever,”, Jan.
2009.
 G. Ateniese, R. Burns, R. Curtmola, J. Herring, L. Kissner, Z.
Peterson, and D. Song, “Provable data possession at untrusted
stores,” in Proc. of CCS’07, Alexandria, VA, October 2007, pp. 598–
609.
 M. A. Shah, R. Swaminathan, and M. Baker, “Privacypreservingaudit
and extraction of digital contents,” Cryptology Print Archive, Report
2008/186, 2008.
 Q. Wang, C. Wang, J. Li, K. Ren, and W. Lou, “Enabling public
verifiability and data dynamics for storage security in cloud
computing,” in Proc. of ESORICS’09, volume 5789 of LNCS.
Springer-Verlag, Sep. 2009, pp. 355–370.

More Related Content

PDF
Propagation urban
PDF
Introduction to IoT Architectures and Protocols
PPT
Ieee 802.11 wireless lan
PPT
Windows V/S Linux OS - Comparison
PPTX
3.pillars of embedded io t and physical devices
DOCX
Library management sytem
PPT
Bluetooth Technology
DOC
Design and implementation of a hospital management system
Propagation urban
Introduction to IoT Architectures and Protocols
Ieee 802.11 wireless lan
Windows V/S Linux OS - Comparison
3.pillars of embedded io t and physical devices
Library management sytem
Bluetooth Technology
Design and implementation of a hospital management system

What's hot (20)

PPTX
Web servers for the Internet of Things
PPT
ManageEngine Applications Manager Overview
PDF
Data engineering zoomcamp introduction
PDF
A survey on Device-to-Device Communication
PDF
Iot lab manual new
PPTX
Washington DC DataOps Meetup -- Nov 2019
PPT
Telecommunication network architecture
DOCX
Unit v
PPTX
mobile phones and tablets.pptx
PPTX
My seminar on bluejacking
PPTX
Seminar on x-max technology ppt
PDF
Online Restaurant Management System
PPS
Project report on mobile shop management
PPTX
SINGLE NODE ARCHITECTURE Hardware components of a sensor node.pptx
PPT
Cluster Computing Seminar.
PDF
Presentation 5G high school
PDF
Latest Research Topics On Flying Ad-Hoc Networks (FANETs):
PPTX
Applications of hybrid systems
DOCX
Computer science seminar topics
Web servers for the Internet of Things
ManageEngine Applications Manager Overview
Data engineering zoomcamp introduction
A survey on Device-to-Device Communication
Iot lab manual new
Washington DC DataOps Meetup -- Nov 2019
Telecommunication network architecture
Unit v
mobile phones and tablets.pptx
My seminar on bluejacking
Seminar on x-max technology ppt
Online Restaurant Management System
Project report on mobile shop management
SINGLE NODE ARCHITECTURE Hardware components of a sensor node.pptx
Cluster Computing Seminar.
Presentation 5G high school
Latest Research Topics On Flying Ad-Hoc Networks (FANETs):
Applications of hybrid systems
Computer science seminar topics
Ad

Viewers also liked (11)

PDF
Maginatics Cloud Storage Platform
PPT
Data encryption standard (des)
PPTX
Data encryption standard
PDF
Cloud Storage for Personal Video Recording
PPTX
Aes (advance encryption standard)
PDF
Challenges Embracing Cloud Storage
PPTX
Cloud storage
PDF
Cloud storage slides
PPTX
Cryptography
DOCX
Assignment cloud storage
Maginatics Cloud Storage Platform
Data encryption standard (des)
Data encryption standard
Cloud Storage for Personal Video Recording
Aes (advance encryption standard)
Challenges Embracing Cloud Storage
Cloud storage
Cloud storage slides
Cryptography
Assignment cloud storage
Ad

Similar to PUBLIC AUDITING FOR SECURE CLOUD STORAGE (20)

PPT
Privacy Preserving Public Auditing for Data Storage Security in Cloud.ppt
PDF
Privacy preserving external auditing for data storage security in cloud
PDF
To Improve Data Storage Security Levels in the Cloud
PDF
IRJET- Continuous Auditing Approach to the Cloud Service Addressing Attri...
PPTX
Privacy preserving public auditing
PDF
Cloud Auditing With Zero Knowledge Privacy
PDF
Privacy preserving public auditing for secure cloud storage
PDF
Public Auditing for Regenerating Code Based Cloud Storage
PDF
IRJET-Survey Paper on Security for Data Storage and Regeneration of Code by A...
PDF
Paper id 212014106
PPT
PDF
Secure Privacy Preserving Using Multilevel Trust For Cloud Storage
PPT
PPT
Privacy preserving public auditing for secure cloud storage
PDF
Third Party Public Auditing Scheme for Security in Cloud Storage
PPTX
Oruta ppt
DOCX
DOTNET 2013 IEEE CLOUDCOMPUTING PROJECT Privacy preserving public auditing fo...
DOCX
JAVA 2013 IEEE CLOUDCOMPUTING PROJECT Privacy preserving public auditing for ...
Privacy Preserving Public Auditing for Data Storage Security in Cloud.ppt
Privacy preserving external auditing for data storage security in cloud
To Improve Data Storage Security Levels in the Cloud
IRJET- Continuous Auditing Approach to the Cloud Service Addressing Attri...
Privacy preserving public auditing
Cloud Auditing With Zero Knowledge Privacy
Privacy preserving public auditing for secure cloud storage
Public Auditing for Regenerating Code Based Cloud Storage
IRJET-Survey Paper on Security for Data Storage and Regeneration of Code by A...
Paper id 212014106
Secure Privacy Preserving Using Multilevel Trust For Cloud Storage
Privacy preserving public auditing for secure cloud storage
Third Party Public Auditing Scheme for Security in Cloud Storage
Oruta ppt
DOTNET 2013 IEEE CLOUDCOMPUTING PROJECT Privacy preserving public auditing fo...
JAVA 2013 IEEE CLOUDCOMPUTING PROJECT Privacy preserving public auditing for ...

Recently uploaded (20)

PPTX
OOP with Java - Java Introduction (Basics)
PPTX
MCN 401 KTU-2019-PPE KITS-MODULE 2.pptx
PPTX
CH1 Production IntroductoryConcepts.pptx
PDF
Evaluating the Democratization of the Turkish Armed Forces from a Normative P...
PPTX
Foundation to blockchain - A guide to Blockchain Tech
PDF
Mohammad Mahdi Farshadian CV - Prospective PhD Student 2026
PDF
Embodied AI: Ushering in the Next Era of Intelligent Systems
DOCX
ASol_English-Language-Literature-Set-1-27-02-2023-converted.docx
PPTX
additive manufacturing of ss316l using mig welding
PPTX
IOT PPTs Week 10 Lecture Material.pptx of NPTEL Smart Cities contd
PPTX
Lecture Notes Electrical Wiring System Components
PPTX
Engineering Ethics, Safety and Environment [Autosaved] (1).pptx
PDF
PPT on Performance Review to get promotions
PPTX
web development for engineering and engineering
PPT
Project quality management in manufacturing
PPTX
M Tech Sem 1 Civil Engineering Environmental Sciences.pptx
PDF
SM_6th-Sem__Cse_Internet-of-Things.pdf IOT
PPTX
MET 305 2019 SCHEME MODULE 2 COMPLETE.pptx
PPTX
Geodesy 1.pptx...............................................
PDF
composite construction of structures.pdf
OOP with Java - Java Introduction (Basics)
MCN 401 KTU-2019-PPE KITS-MODULE 2.pptx
CH1 Production IntroductoryConcepts.pptx
Evaluating the Democratization of the Turkish Armed Forces from a Normative P...
Foundation to blockchain - A guide to Blockchain Tech
Mohammad Mahdi Farshadian CV - Prospective PhD Student 2026
Embodied AI: Ushering in the Next Era of Intelligent Systems
ASol_English-Language-Literature-Set-1-27-02-2023-converted.docx
additive manufacturing of ss316l using mig welding
IOT PPTs Week 10 Lecture Material.pptx of NPTEL Smart Cities contd
Lecture Notes Electrical Wiring System Components
Engineering Ethics, Safety and Environment [Autosaved] (1).pptx
PPT on Performance Review to get promotions
web development for engineering and engineering
Project quality management in manufacturing
M Tech Sem 1 Civil Engineering Environmental Sciences.pptx
SM_6th-Sem__Cse_Internet-of-Things.pdf IOT
MET 305 2019 SCHEME MODULE 2 COMPLETE.pptx
Geodesy 1.pptx...............................................
composite construction of structures.pdf

PUBLIC AUDITING FOR SECURE CLOUD STORAGE

  • 1. PUBLIC AUDITING FOR SECURE CLOUD STORAGE Anand K Menon[MTALECS004 ] Bharath Chandran Nair[MTALECS015] Godwin C Antony[MTALECS025] Eighth semester B.Tech CSE, Department of Computer Science, Met’s School of Engineering,Mala, Under the Guidance of Miss.Asha S Assistant Professor, Dept. of CSE, Met’s School of Engineering,Mala
  • 2. OUTLINE OF THE PRESENTATION o OBJECTIVE o INTRODUCTION o LITERATURE SURVEY o EXISTING METHOD o PROBLEM DESCRIPTION o BLOCK DIAGRAM o PROPOSED METHOD o APPLICATIONS o RESULT AND DISCUSSION OF BASE PAPER o EXECUTION TOOLS o CONCLUSION o REFERENCES
  • 3. OBJECTIVE  The objective of the system is to develop a system that would enable the cloud users to have control over their data so that they can ensure that their data is secured and not corrupted.  It provides security to the users data by encrypting the data and splitting up the file into small blocks for storage.  Auditing the cloud storage without demanding a local copy of data enables more efficiency.
  • 4. INTRODUCTION  Cloud computing customers do not own a physical infrastructure; rather they rent the usage from a third party provider.  They consume resources as a service and pay only for resources that they use.  Cloud computing comes in three forms: public clouds, private clouds, and hybrids clouds.  Public clouds offer the greatest level of efficiency in shared resources but are more vulnerable.  Private clouds offer the greatest level of security and control, but they require the company to still purchase and maintain all the software and infrastructure.  Hybrid cloud includes both public and private options.The downside is that we have to keep track of multiple different security platforms.
  • 5.  Cloud computing provides on demand self services,location independent resource pooling,rapid resource elasticity,usage based pricing etc..  Challenge faced is security threats towards users outsourced data.  Here the correctness of user data in the cloud is put at risk.  CSP might reclaim storage for monetary reasons by discarding rarely accesed data or even hiding data corruption due to server hacks over byzantine failures.
  • 6. LITERATURE REVIEW SL .N O AUTHOR YEAR TITLE DESCRIPTION 1 P. Mell and T. Grance June 2009 DraftNISTworking definitionofcloud computing Subscribers should identify the specific resources that are suitable for migrating data into and out of clouds. Resources could be services such as: (1) email, (2) data repositories such as shared documents, or (3) systems that run in virtualized environments. 2 M. Arrington December 2006 Gmail disaster: Reports of mass email deletions Cloud Computing provides convenient on demand network access to a shared pool of configurable computing resources that can be rapidly deployed with the great efficiency and minimal management overhead. 3 J. Kincaid December 2006. MediaMax/TheLinkup Closes Its Doors To achieve the assurances of cloud data integrity and availability and enforce the quality of dependable cloud storage service for users, To propose an effective and flexible distributed scheme with explicit dynamic data support, including block update, delete, and append.
  • 7. LITERATURE REVIEW S L . N O AUTHOR YEAR TITLE DESCRIPTION 4 M.A.Shah,R.Swamina than, and M. Baker Oct. 2008 Privacy-preserving audit and extraction of digital contents A growing number of online services, such as Google, Yahoo!, and Amazon, are starting to charge users for their storage. Customers often use these services to store valuable data such as email, family photos and videos, and disk backups. Today, a customer must entirely trust such external services to maintain the integrity of hosted data and return it intact. 5 Q. Wang, C. Wang, J. Li, K. Ren, and W. Lou Sep. 2009 Enabling publicverifiability and data dynamics for storage security in cloud computing Cloud Computing has been envisioned as the next-generation architecture of IT Enterprise. It moves the application software and databases to the centralized large data centers, where the management of the data and services may not be fully trustworthy. 6 G. Ateniese, S. Kamara, and J. Katz 2009 Proofs of storage fromhomomorphic identification protocols Proofs of storage (PoS) are interactive protocols allowing a client to verify that a server faithfully stores a file. Previous work has shown that proofs of storage can be constructed from any homomorphic linear authenticator (HLA). The latter, roughly speaking, are signature/message authentication schemes where `tags' on multiple messages can be homomorphically combined to yield a `tag' on any linear combination of these messages.
  • 8. 8 BASIC SCHEME 1 MAC key File block code Message Authentication Code (MAC) Block 1 Block nBlock 2 … File is divided into blocks Cloud user TPA Block 1 Block n…Block 2 code 1 code n…code 2 -User computes the MAC of every file block -Transfers the file blocks & codes to cloud -Shares the key with TPA Audit -TPA demands a random number of blocks and their code from CSP -TPA uses the key to verify the correctness of the file blocks Drawbacks: -The audit demands retrieval of user’s data; this is not privacy-preserving -Communication and computation complexity are linear with the sample size EXISTING METHOD
  • 9. 9 BASIC SCHEME 2 Block 1 Block n…Block 2 code 1 code n…code 2 code 1 code n…code 2 code 1 code n…code 2 Key 1 Key 2 Key s … user Cloud TPA Block 1 Block m…Block 2 Setup -User uses s keys and computes the MAC for blocks -User shares the keys and MACs with TPA Audit -TPA gives a key (one of the s keys) to CSP and requests MACs for the blocks -TPA compares with the MACs at the TPA -Improvement from Scheme 1: TPA doesn’t see the data, preserves privacy -Drawback: a key can be used once. -The TPA has to keep a state; remembering which key has been used -Schemes 1 & 2 are good for static data (data doesn’t change at the cloud)
  • 10. PROBLEM DESCRIPTION  Audit cloud storage demanding local copy of data.  Violates the privacy-preserving guarantee.  Large communication overhead and time delay.  Band-width available between the TPA and the cloud server is limited.  Auditor can modify user data.  Copy of user data on auditing side.  No data control on user side.  The number of times a particular data file can be audited is limited by the number of secret key.
  • 11. BLOCK DIAGRAM U: cloud user has a large amount of data files to store in the cloud CS: cloud server which is managed by the CSP and has significant data storage and computing power (CS and CSP are the same in this paper) TPA: third party auditor has expertise and capabilities that U and CSP don’t have. TPA is trusted to assess the CSP’s storage security upon request from U
  • 12. Setup & audit phases of public auditing scheme.
  • 13.  Consists of four algorithms (KeyGen, SigGen, GenProof, VerifyProof)  KeyGen: key generation algorithm that is run by the user  SigGen: used by the user to generate verification metadata, which may consist of MAC, signatures or other information used for auditing  GenProof: run by the cloud server to generate a proof of data storage correctness  VerifyProof: run by the TPA to audit the proof from the cloud server
  • 14. 14 user KeyGen Public key (sk)& Secret key (pk) Setup SigGenuser sk Block 1 Block 2 Block n… σ1 …σ2 σn Block 1 Block n…Block 2 σ1 … σnσ2 1- User generates public and secret parameters 2- A code is generated for each file block 3- The file blocks and their codes are transmitted to the cloud Audit -TPA sends a challenge message to CSP -It contains the position of the blocks that will be checked in this audit GenProofCSP Selected blocks in challenge Aggregate authenticator -CSP also makes a linear combination of selected blocks and applies a mask. Separate PRF key for each auditing. -CSP send aggregate authenticator & masked combination of blocks to TPA VerifyProofTPA Masked linear combination of requested blocks Aggregate authenticator Compare the obtained Aggregate authenticator to the one received from CSP
  • 15. PROPOSED METHOD  Public auditing scheme which provides a complete outsourcing solution of data– not only the data itself, but also its integrity checking  System consist of client and server side application and website.  Effectively audit cloud storage without demanding local copy of data.  Extensive security and performance analysis shows provably secure and highly efficient.  Data conrtol in the hands of users only.
  • 16. APPLICATIONS  Used in applications that require public auditing.  Can be used for batch auditing.  Application that ensures storage correctness.
  • 20.  Checking the Security Status
  • 23. TPA MODULE (THIRD PARTY AUDITOR):
  • 25. CSP MODULE (CLOUD SERVICE PROVIDER):
  • 28. DISCUSSION OF BASE PAPER Objective of the Project  The objective of the system is to develop a system that would enable the cloud users to have control over their data so that they can ensure that their data is secured and not corrupted. Scope of the Project  “ Trusted Cloud Services” provides a security solution to the cloud users. It ensures that the data of the users that have been stored in a remote server is secured and controlled.
  • 29. Constraints  Only the registered users will be authorized to use the service.  A trustworthy TPA is required to audit the storage. Assumptions and dependencies  The project will not change in scope  The resources identified will be available upon request  Approved funding will be available upon request  Only the registered users can access the Website  Roles and tasks are predefined.
  • 30. EXECUTION TOOLS Hardware Requirements  Intel Pentium dual core processor or above  1 GB RAM  200 GB HDD  Other standard peripherals Software Requirements  Operating system : windows XP  Tool: Netbeans IDE 6.1  Programming Package : Jdk.5.0  Database :MySQL  Server :Glassfish v2
  • 31. CONCLUSION  The aim of the project is to develop a system that would enable the cloud users to have control over their data so that they can ensure that their data is secured .  They can know whether there is any data loss or corruption by logging into the website.  TPA would not learn any knowledge about the data content stored on the cloud server during the efficient auditing process.  TPA can perform multiple auditing tasks in a batch manner for better efficiency.  Schemes are provably secure and highly efficient.
  • 41. REFERENCE  P. Mell and T. Grance, “Draft NIST working definition of cloud computing,” Referenced on June. 3rd, 2009 Online at http://csrc.nist.gov/groups/SNS/cloud-computing/index. html, 2009.  M. Armbrust, A. Fox, R. Griffith, A. D. Joseph, R. H. Katz, A. Konwinski, G. Lee, D. A. Patterson, A. Rabkin, I. Stoica, and M. Zaharia, “Above the clouds: A berkeley view of cloud computing,” University of California, Berkeley, Tech.  M. Arrington, “Gmail disaster: Reports of mass email deletions,” Online at http://www.techcrunch.com/2006/12/28/gmail- disasterreports-of-mass-email-deletions/,December 2006.  J. Kincaid, “MediaMax/TheLinkup Closes Its Doors,” Online at http://www.techcrunch.com/2008/07/10/ mediamaxthelinkup-closes- its-doors/, July 2008.  Amazon.com, “Amazon s3 availability event: July 20, 2008,” Online at http://status.aws.amazon.com/s3-20080720.html,2008.
  • 42.  S. Wilson, “Appengine outage,” Online at http://www.cio- weblog.com/50226711/appengine outage.php, June 2008.  B. Krebs, “Payment Processor Breach May Be Largest Ever,”, Jan. 2009.  G. Ateniese, R. Burns, R. Curtmola, J. Herring, L. Kissner, Z. Peterson, and D. Song, “Provable data possession at untrusted stores,” in Proc. of CCS’07, Alexandria, VA, October 2007, pp. 598– 609.  M. A. Shah, R. Swaminathan, and M. Baker, “Privacypreservingaudit and extraction of digital contents,” Cryptology Print Archive, Report 2008/186, 2008.  Q. Wang, C. Wang, J. Li, K. Ren, and W. Lou, “Enabling public verifiability and data dynamics for storage security in cloud computing,” in Proc. of ESORICS’09, volume 5789 of LNCS. Springer-Verlag, Sep. 2009, pp. 355–370.