Post on 26-May-2015
description
By,
S.Kayalvizhi Sharmila
PRIVACY-PRESERVING PUBLIC AUDITING FOR
DATA STORAGESECURITY IN CLOUD
COMPUTING
ABSTRACT
Cloud Computing, enabling convenient network access to a shared pool of configurable computing resources
Enabling public auditability, so that users can resort to an external audit party to check the integrity of outsourced data when needed.
TPA audit the cloud data storage without demanding the local copy of data, and introduce no additional on-line burden to the cloud user.
OUR CONTRIBUTION
The scheme supports an external auditor to audit user’s outsourced data in the cloud without learning knowledge on the data content.
Achieves batch auditing where multiple delegated auditing tasks from different users can be performed simultaneously by the TPA.
To prove the security and justify the performance of proposed schemes through concrete experiments and comparisons with the state-of-the-art.
THIRD PARTY AUDITOR (TPA)
Third Party Auditor (TPA) TPA helps the user to audit the data To allow TPA securely: 1) TPA should audit the data from the cloud, not ask
for a copy 2) TPA should not create new vulnerability to user
data privacy This paper presents a privacy-preserving public
auditing system for cloud data storage
Cloud network
Data use
r
user
user
External Audit party
ARCHITECTURE
DESIGN GOALS
I. Public auditabilityII. Storage correctnessIII. Privacy-preservingIV. Batch auditingV. Lightweight
THE EXISTING SYSTEM
THE PROPOSED SCHEME
We utilize the public key based homomorphic authenticator and uniquely integrate it with random mask technique.
TPA can perform multiple auditing tasks simultaneously.
Four algorithmsKeyGen, SigGen, GenProof, VerifyProof.
FIG: PROPOSED SYSTEM
PRIVACY-PRESERVING PUBLIC AUDITING MODULE:
Homomorphic authenticators are unforgeable verification metadata.
Block 1 Block 2 Block k…
Verification Metadata
Verification Metadata
Verification Metadata
Aggregate Verification Metadata
A linear combination of data blocks can be verified by looking only at the aggregated authenticator
Homomorphic authenticator
11
Setup
Audit
user KeyGen
Public & Secretparameters
SigGen File F
Verification Metadata
TPA
TPA issues an audit message or a challenge to CSP
GenProof
VerifyProof
CSP
TPA
File F
Response message
Verification Metadata
Phases
MORE EXTENSIONS
Batch auditing There are K users having K files on the same cloud They have the same TPA Then, the TPA can combine their queries and save in
computation time The comparison function that compares the aggregate
authenticators has a property that allows checking multiple messages in one equation
Instead of 2K operation, K+1 are possible
Data dynamics The data on the cloud may change according to applications This is achieved by using the data structure Merkle Hash
Tree (MHT) With MHT, data changes in a certain way; new data is added
in some places There is more overhead involved ; user sends the tree root
to TPA
CONCLUSION
Utilizing the homomorphic authenticator and random mask technique to guarantee that TPA would not learn any knowledge about the data content
Considering TPA may concurrently handle multiple audit sessions from different users for their outsourced data files
Thank You