1. Presented by:
C.SUCHITHRA
Department of Computer Science
Dr. Pauls Engineering College
Guided by:
Mr. G. APPASAMI M.Tech.,
(Ph.D.,)
Assistant Professor (CSE),
Dr. Pauls Engineering College

2. ABSTRACT
INTRODUCTION
EXISTING SYSTEM
PROPOSED SYSTEM
SYSTEM MODEL
DESIGN GOALS
SIMULATION RESULTS
CONCLUSION

3.  Due to the frequent change of the membership, sharing data in a
multi-owner manner is a major problem in cloud computing.
 Identity privacy and Privacy preserving from an untrusted cloud
is still a challenging issue.
 By Leveraging Group Signature and Dynamic Broadcast
encryption techniques, any cloud user can anonymously share
data with others.

4.  The main aim is to secure data sharing in dynamic groups, there is
no fixed attributes whereas multi-owner attributes is possible.
 Meanwhile, the storage overhead and encryption computation cost
of the scheme are independent with the number of revoked users.
 It also analyze the security of scheme with rigorous proof and
demonstrate the efficiency in experiment.

5.  It consists of H/w & S/w resources
made available on the internet as
managed third-party services.
 These service typically provide access
to advanced s/w application & high-
end network of server computers.

6.  An Internet connection
 An account - Created with a user name and a password
 Agree to Terms

7.  Can be less expensive compared to
buying software and hardware.
 Can be used from any computer or
device with an Internet
connection.
 The device does not need as large
of an internal storage system.
Anywhere
at any
time
Sharing
Work
wherever
you are
Collaboration

8.  The most fundamental services offered by cloud providers is
data storage.
 With cloud computing and storage, users are able to access and
to share resources offered by cloud service providers at a lower
marginal cost.
 Cloud-based service providers are globally connected to each
other and offer a seamless service to their customers.

9.  In the existing system data owners store the encrypted data files in
untrusted storage and distribute the corresponding decryption keys
only to authorized users.
 The complexities of user participation and revocation in these
schemes are linearly increasing with the number of data owners and
the number of revoked users.
 The changes of membership make secure data sharing extremely
difficult and the issue of user revocation is not addressed.

10.  Identity privacy is one of the most significant obstacles for the
wide deployment of cloud computing.
 Without the guarantee of identity privacy, users may be
unwilling to join in cloud computing systems.
 Because their real identities could be easily disclosed to cloud
providers and attackers.
 On the other hand, unconditional identity privacy may incur
the abuse of privacy.

11.  Attribute based encryption technique new granted users can
directly decrypt data files and uploaded before their participation
without contacting with data owners.
 User revocation can be easily achieved through a novel
revocation list without updating the secret keys of the remaining
users.
 The size and computation overhead of encryption are constant
and independent with the number of revoked users.
 Its provide secure and privacy-preserving access control to users.

12.  Moreover, the real identities of data owners can be revealed by
the group manager when disputes occur.
 Compared with the Single-owner, Multiple-owner is more
flexible in practical applications.
 Each user in the group is able to not only read data , but also
modify his/her part of data in the entire data file shared by the
company.

13.  Any user in the group can store and share data files with others
by the cloud.
 The encryption complexity and size of cipher texts are
independent with the number of revoked users in the system.
 User revocation can be achieved without updating the private
keys of the remaining users.

14. GROUP SIGNATURE
 Allows any member of the group to sign messages while keeping
the identity secret from verifiers.
 Besides, the designated group manager can reveal the identity of
the signature’s originator when a dispute occurs.
 Used to achieve anonymous access control.

15. DYNAMIC BROADCAST ENCRYPTION
 To transmit encrypted data to a set of users so that only a
privileged subset of users can decrypt the data.
 It also allows the group manager to dynamically include new
members while preserving previously computed information.

17. The system model consists of five different entities
• The cloud Server,
• Group Manager (i.e., the company manager)
• Group Members (i.e., the staffs)
• Key distribution
• Revocation

18.  Access control
 Data confidentiality
 Anonymity and Traceability
 Efficiency

19. Comparison on computation cost for file
generation between Innovative and ODBE

20. Comparison on computation cost for file
access between Innovative and ODBE.

25.  This work designs a secure data sharing scheme, for
dynamic clusters in an untrusted cloud.
 A user is able to share data with others in the group without
revealing identity privacy to the cloud.
 Additionally, it supports efficient user revocation and new
user joining.
 Moreover, the storage overhead and the encryption
computation cost are constant.
 Extensive analyses show that this proposed scheme satisfies
the desired security requirements and guarantees efficiency
as well

26. T

27. QUERIES ???