KAC-An Associate Approach for

Data Sharing in Cloud Storage

First Review

Abstract

Data sharing is an important functionality in

cloud storage.

In this paper, we show how to securely,

efficiently, and flexibly share data with others

in cloud storage.

We describe new public-key cryptosystems that

produce constant-size cipher texts such that

efficient delegations of decryption rights for

any set of cipher texts are possible.

Existing System

A cryptographic solution, with proven security

relied on number-theoretic assumptions is more

desirable, whenever the user is not perfectly

happy with trusting the security of the VM or

the honesty of the technical staff.

These users are motivated to encrypt their data

with their own keys before uploading them to

the server.

Disadvantage

The costs and complexities involved generally

increase with the number of the decryption

keys to be shared.

The encryption key and decryption key are

different in publickey encryption.

Proposed System

In this paper, we study how to make a decryption key

more powerful in the sense that it allows decryption

of multiple ciphertexts, without increasing its size.

Specifically, our problem statement is

“To design an efficient public-key encryption scheme

which supports flexible delegation in the sense that

any subset of the ciphertexts (produced by the

encryption scheme) is decry ptable by a constant-size

decryption key (generated by the owner of the master-

secret key).”

Proposed System

We solve this problem by introducing a special

type of public-key encryption which we call

key-aggregate cryptosystem (KAC).

System Architecture

Literature Survey

Analysis and Security based on Attribute based Encryption for

data Sharing (ISSN: 2278-9359 (Volume-3, Issue-3)

Ciphertext policy attribute based encryption with efficient

revocation

Cryptosystem for Secure Data Sharing in Cloud Storage (2014

IJIRT , Volume 1 Issue 6 , ISSN: 2349-6002)

1.Analysis and Security based on Attribute based

Encryption for data Sharing

The key-policy attribute are used for describing

encrypting data and policy implemented in user`s key,

and the cipher text policy is the access structure on the

cipher text. And the access structure can also be present

in either monotonic or non-monotonic.

2.Ciphertext policy attribute based

encryption with efficient revocation

Ciphertext Policy Attribute Based Encryption

(CPABE) enables users’ encryption with an

accessstructure while assigning decryption

capability in accordance with attribute sets.

In this paper, we study central-control

revocation in CPABE environment, where the

proposed key generation, encryption and

decryption algorithms closely comply with

CPABE model

3.Cryptosystem for Secure Data

Sharing in Cloud Storage

To achieve a secure and dependable cloud storage

service, a secure multi-owner data sharing scheme is

proposed according to any user in the group so that they

can securely share data with others users by the un-

trusted cloud.

Modules

1. Authentication And Authorization

2. File Encryption by KAC

3. Cloud data sharing

4. File Decryption by KAC

Authentication And Authorization

Authentication and Authorization process are the required of

the Verifying the User Originality and Appropriate Session

Activities of the Registered User.

File Encryption by KAC

After user login, the user can able to store the files into the cloud

in an encryption manner. So that the encrypted files which are

stored in the cloud cannot be decrypted normally by other users

or hacker’s.

Cloud data sharing:

The user initially upload’s files data to the cloud, and

shares it with other users. The shared files are encrypted

by the owner. So whenever the other user’s want to

access or decrypt the file required keys permission to be

accessed.

File Decryption by KAC:

The aggregate keys are sent in mail to other user by the

original user. The file will be decrypted by the aggregate

key’s which was generated by the KAC.

Finally, any user with an aggregate key can decrypt any

cipher text provided that the cipher text’s class is

contained in the aggregate key via Decrypt.

Hardware Reqirements

SYSTEM : Pentium Dual-Core CPU

E5400 2.70GHZ

HARD DISK : 40 GB

MONITOR : 15 VGA colour

MOUSE : Logitech.

RAM : 2 GB

KEYBOARD : 110 keys enhanced.

Software Reqirements

Operating system : Windows 8

Coding Language : Java

Front End : Java Server Page

Front End Tool : Net beans 7.0 IDE

Back End DB : mysql

Database GUI : Sqlyog.

Conclusion

With more mathematical tools, cryptographic schemes aregetting more versatile and often involve multiple keys for asingle application.

In this project, we proposed KAC and how to “compress”secret keys in public-key cryptosystems which supportdelegation of secret keys for different cipher text classes incloud storage.

No matter which one among the power set of classes, thedelegatee can always get an aggregate key of constant size.

Our approach is more flexible than hierarchical keyassignment which can only save spaces if all key-holders sharea similar set of privileges.

THANK YOU