This is a ppt made by shrihari ,in this encryption with privacy preserving in clouds is described!
It will be helpfull for those who are doing projects on cloud!
2. ๏ Introduction
๏ Existing System
๏ Secure cloud storage model
๏ Proposed work
๏ Secure Hash Algorithm
๏ Paillier Algorithm
๏ Conclusion
OVERVIEW
3. INTRODUCTION
๏ A new decentralized access control schema.
๏ Distributed access control so that only users with
valid attributes can access them.
๏ Support the creation, modification and reading the
data stored in the cloud
4. EXISTING SYSTEM
๏ The existing access control in cloud are centralized in
nature.
๏ This scheme uses a symmetric key approach.
๏ This approach does not support the authentication.
13. H. Paillier Algorithm
Key generation
Step 1: Choose two large prime numbers p and q randomly and
independently of each other such that gcd (pq, (p-1)(q-1))=1.
This property is assured if both primes are of equal length.
Step 2: Compute n=pq and ฮป=lcm(p-1,q-1).
Step 3: Select random integer g where gZ*n2.
Step 4: Ensure n divides the order of g by checking the existence
of the following modular multiplicative inverse
ฮผ= (L(gฮป mod n2))-1mod n.
where function L is defined as L(u)= (u-1)/n.
14. Encryption
โข Let m be a message to be encrypted where m Zn.
โข Select random r where r Z*n.
โข Compute cipher text as: c= ek (x; r ) = gm.rn mod n2
Decryption
โข Cipher text: cZ*n2.
โข Compute message: m=dk(y)= (L(yฮป mod n2 ))/((L(gฮป
mod n2 )) mod n.
Contd โฆ
15. CONCLUSION
โข A decentralized access control technique with anonymous
authentication.
โข Provides user revocation.
โข The cloud does not know the identity of the user who stores
information, but only verifies the userโs credentials.
โข One limitation is that the cloud knows the access policy for
each record stored in the cloud.
16. Future Work
๏ In future, using SQL queries for hide the attributes and
access policy of a user.
๏ Files stored in cloud can be corrupted. So for this issue
using the file recovery technique to recover the corrupted
file successfully and to hide the access policy and the user
attributes