Attribute-Based
Encryption With Verifiable Outsourced Decryption
ABSTRACT:
Attribute-based encryption
(ABE) is a public-keybased one-to-many encryption that allows users to encrypt
and decrypt data based on user attributes. A promising application of ABE is
flexible access control of encrypted data stored in the cloud, using access
polices and ascribed attributes associated with private keys and
ciphertexts.One of themain efficiency drawbacks of the existing ABE schemes is
that decryption involves expensive pairing operations and the number of such
operations grows with the complexity of the access policy. Recently, Green et
al. proposed an ABE system with outsourced decryption that largely
eliminates the decryption overhead for users. In such a system, a user provides
an untrusted server, say a cloud service provider, with a transformation key
that allows the cloud to translate any ABE ciphertext satisfied by that user’s
attributes or access policy into a simple ciphertext, and it only incurs a
small computational overhead for the user to recover the plaintext from the
transformed ciphertext. Security of an ABE system with outsourced decryption ensures
that an adversary (including a malicious cloud) will not be able to learn
anything about the encrypted message; however, it does not guarantee the
correctness of the transformation done by the cloud. In this paper, we consider
a new requirement of ABE with outsourced decryption: verifiability. Informally,
verifiability guarantees that a user can efficiently check if the
transformation is done correctly. We give the formal model of ABE with
verifiable outsourced decryption and propose a concrete scheme. We prove that
our new scheme is both secure and verifiable, without relying on random
oracles. Finally, we show an implementation of our scheme and result of
performance measurements, which indicates a significant reduction on computing
resources imposed on users.
EXISTING SYSTEM:
Green et al. proposed
an ABE system with outsourced decryption that largely eliminates the decryption
overhead for users. In such a system, a user provides an untrusted server, say
a cloud service provider, with a transformation key that allows the cloud to
translate any ABE ciphertext satisfied by that user’s attributes or access policy
into a simple ciphertext, and it only incurs a small computational overhead for
the user to recover the plaintext from the transformed ciphertext.
DISADVANTAGES
OF EXISTING SYSTEM:
One of the main efficiency drawbacks of the most
existing ABE schemes is that decryption is expensive for resource-limited devices
due to pairing operations, and the number of pairing operations required to
decrypt a ciphertext grows with the complexity of the access policy. At the
cost of security, only proven in a weak model (i.e., selective security), there
exist several expressive ABE schemes where the decryption algorithm only
requires a constant number of pairing computations.
PROPOSED SYSTEM:
In this paper, we first modify the original model of
ABE with outsourced decryption in existing system to allow for verifiability of
the transformations. After describing the formal definition of verifiability,
we propose a new ABE model and based on this new model construct a concrete ABE
scheme with verifiable outsourced decryption. Our scheme does not rely on
random oracles.
ADVANTAGES
OF PROPOSED SYSTEM:
ü Proposed
scheme does not rely on random oracles
ü The
scheme substantially reduced the computation time required for resource-limited
devices to recover plaintexts.
SYSTEM ARCHITECTURE:
ALGORITHMS USED:
ü Setup
ü KeyGen
ü Encrypt
ü Decrypt
ü GenTK
ü Transform
ü Decrypt
out
SYSTEM CONFIGURATION:-
HARDWARE CONFIGURATION:-
ü Processor - Pentium –IV
ü Speed - 1.1
Ghz
ü RAM - 256
MB(min)
ü Hard Disk -
20 GB
ü Key Board -
Standard Windows Keyboard
ü Mouse - Two
or Three Button Mouse
ü Monitor - SVGA
SOFTWARE CONFIGURATION:-
ü Operating System : Windows XP
ü Programming Language :
JAVA/J2EE.
ü Java Version :
JDK 1.6 & above.
ü Database :
MYSQL
REFERENCE:
Junzuo Lai, Robert H. Deng, Chaowen Guan, and Jian
Weng, “Attribute-Based Encryption With Verifiable Outsourced Decryption”, IEEE TRANSACTIONS ON INFORMATION FORENSICS
AND SECURITY, VOL. 8, NO. 8, AUGUST 2013.