Circuit Cipher text-policy Attribute-based Hybrid Encryption with Verifiable Delegation in Cloud Computing

Abstract

In the cloud, for achieving access control and keeping data confidential, the data owners could adopt attribute-based encryption to encrypt the stored data. Users with limited computing power are however more likely to delegate the mask of the decryption task to the cloud servers to reduce the computing cost. As a result, attribute-based encryption with delegation emerges. Still, there are caveats and questions remaining in the previous relevant works. For instance, during the delegation, the cloud servers could tamper or replace the delegated cipher text and respond a forged computing result with malicious intent. They may also cheat the eligible users by responding them that they are ineligible for the purpose of cost saving. Furthermore, during the encryption, the access policies may not be flexible enough as well. Since policy for general circuits enables to achieve the strongest form of access control, a construction for realizing circuit cipher text-policy attribute-based hybrid encryption with verifiable delegation has been considered in our work. In such a system, combined with verifiable computation and encrypt-then-Mac mechanism, the data confidentiality, the fine-grained access control and the correctness of the delegated computing results are well guaranteed at the same time. Besides, our scheme achieves security against chosen-plaintext attacks under the k-multi linear Decisional Diffie-Hellman assumption. Moreover, an extensive simulation campaign confirms the feasibility and efficiency of the proposed solution.

Aim

The main aim is to provide an efficient method to share and protect the confidential information between users with limited power and data owners with vast amount of data in the cloud.

Scope

The scope is to provide policy for general circuits enables to achieve the strongest form of access control, a construction for realizing circuit cipher text-policy attribute-based hybrid encryption with verifiable delegation has been considered.

Existing System

Attribute-based encryption

Proposed the notion of attribute-based encryption (ABE).They focused on policies across multiple authorities and the issue of what expressions they could achieve. Up until recently, raised a construction for realizing KPABE for general circuits. Prior to this method, the strongest form of expression is boolean formulas in ABE systems, which is still a far cry from being able to express access control in the form of any program or circuit. Actually, there still remain two problems. The first one is their have no construction for realizing CPABE for general circuits, which is conceptually closer to traditional access control. The other is related to the efficiency, since the exiting circuit ABE scheme is just a bit encryption one. Thus, it is apparently still remains a pivotal open problem to design an efficient circuit CP-ABE scheme.

Hybrid encryption.

Existing system proposed the generic KEM/DEM construction for hybrid encryption which can encrypt messages of arbitrary length. Based on their ingenious work, a one-time MAC were combined with symmetric encryption to develop the KEM/DEM model for hybrid encryption. Such improved model has the advantage of achieving higher security requirements. ABE with Verifiable Delegation. Since the introduction of ABE, there have been advances in multiple directions.The application of outsourcing computation is one of an important direction. It designed the first ABE  with outsourced decryption scheme to reduce the computation cost during decryption. However, since the data owner generates a commitment without any secret value about his identity, the untrusted server can then forge a commitment for a message he chooses. Thus the ciphertext relating to the message is at risk of being tampered. Further more, just modify the commitments for the ciphertext relating to the message is not enough. The cloud server can deceive the user with proper permissions by responding the terminator ⊥ to cheat that he/she is not allowed to access to the data.

Disadvantages

There are caveats and questions remaining in the previous relevant works. For instance, during the delegation, the cloud servers could tamper or replace the delegated cipher text and respond a forged computing result with malicious intent. They may also cheat the eligible users by responding them that they are ineligible for the purpose of cost saving. Furthermore, during the encryption, the access policies may not be flexible enough as well.

Proposed System

This project proposes a concrete circuit ciphertext-policy attribute-based hybrid encryption with verifiable delegation scheme based on the multilinear maps and the verifiable computing technology under cloud environment.

Advantages

• This project achieves security against chosen-plaintext attacks under the k-multi linear Decisional Diffie-Hellman assumption. Moreover, an extensive simulation campaign confirms the feasibility and efficiency of the proposed solution.
•   An extensive simulation campaign confirms the feasibility and efficiency.

System Architecture

System Configuration

Hardware Requirements

• Speed                        -   1.1 Ghz
• Processor              - Pentium IV
• RAM                         -   512 MB (min)
• Hard Disk         -    40 GB
• Key Board                 -     Standard Windows Keyboard
• Mouse                       -    Two or Three Button Mouse
• Monitor                     -     LCD/LED

 Software requirements

• Operating System              : Windows 7             
•  Front End                           : ASP.Net and C#
• Database                             : MSSQL
• Tool                                    : Microsoft Visual studio

References

Wen, Q. , Li, W. , Jin, Z., Xu, J. “CIRCUIT CIPHER TEXT-POLICY ATTRIBUTE-BASED HYBRID ENCRYPTION WITH VERIFIABLE DELEGATION IN CLOUD COMPUTING”          Parallel and Distributed Systems, IEEE Transactions on  (Volume:PP ,  Issue: 99 ) January 2015.