Showing posts with label JAVA project thesis work. Show all posts

Wednesday, 21 October 2015

Contributory Broadcast Encryption With Efficient Encryption And Short Cipher Texts

ABSTRACT

Traditional broadcast encryption (BE) schemes allow a sender to securely broadcast to any subset of members but require a trusted party to distribute decryption keys. Group key agreement (GKA) protocols enable a group of members to negotiate a common encryption key via open networks so that only the group members can decrypt the cipher texts encrypted under the shared encryption key, but a sender cannot exclude any particular member from decrypting the cipher texts. In this paper, we bridge these two notions with a hybrid primitive referred to as contributory broadcast encryption (ConBE). In this new primitive, a group of members negotiate a common public encryption key while each member holds a decryption key. A sender seeing the public group encryption key can limit the decryption to a subset of members of his choice. Following this model, we propose a ConBE scheme with short ciphertexts. The scheme is proven to be fully collusion-resistant under the decision n-Bilinear Diffie-Hellman Exponentiation (BDHE) assumption in the standard model. Of independent interest, we present a new BE scheme that is aggregatable. The aggregatability property is shown to be useful to construct advanced protocols.

AIM

The aim of this paper is a group of members negotiate a common public encryption key while each member holds a decryption key. A sender seeing the public group encryption key can limit the decryption to a subset of members of his choice.

SCOPE:

The Scope of this Paper is proven to be fully collusion-resistant under the decision n-Bilinear Diffie-Hellman Exponentiation (BDHE) assumption in the standard model.

EXISTING SYSTEM

BE schemes in the literature can be classified into two categories, i.e., symmetric-key BE and public-key BE . In the symmetric-key setting, only the trusted center generates all the secret keys and broadcasts messages to users. Hence, only the key generation center can be the broadcaster or the sender. Similarly to the GKA setting, tree-based key structures were independently proposed to improve efficiency in symmetric-key BE systems and further improved in with O(log n) keys. Cheon et al.presented an efficient symmetric BE scheme allowing new members to join the protocol anytime. Harn and Lin proposed a group key transfer protocol. Their protocol is based on secret sharing and is considerably efficient, albeit it cannot revoke (compromised) users

DISADVANTAGES

Group key agreement (GKA) protocols enable a group of members to negotiate a common encryption key via open networks so that only the group members can decrypt the cipher texts encrypted under the shared encryption key but a sender cannot exclude any particular member from decrypting the cipher texts.
A BE system heavily relies on a fully trusted key server who generates secret decryption keys for the members and can read all the communications to any members.

PROPOSED SYSTEM

In this paper, construct an efficient ConBE scheme with our AggBE scheme as a building block. The ConBE construction is proven to be semi-adaptively secure under the decision BDHE assumption in the standard model. Only one round is required to establish the public group encryption key and set up the ConBE system. After the system set-up, the storage cost of both the sender and the group members is O(n), where n is the number of group members participating in the setup stage. However, the online complexity (which dominates the practicality of a ConBE scheme) is very low. We also illustrate a trade-off between the set-up complexity and the online performance. After a trade-off, the variant has O(n2=3) complexity in communication, computation and storage. This is comparable to up-to-date regular BE schemes which have O(n1=2) complexity in the same performance metrics, but our scheme does not require a trusted key dealer. We conduct a series of experiments and the experimental results validate the practicality of our scheme.

ADVANTAGES

In ConBE, anyone can send secret messages to any subset of the group members, and the system does not require a trusted key server.

As a versatile cryptographic primitive, our novel ConBE notion opens a new avenue to establish secure broadcast channels and can be expected to secure numerous emerging distributed computation applications.

SYSTEM CONFIGURATION

HARDWARE REQUIREMENTS:-

· Processor - Pentium –III

· Speed - 1.1 Ghz

· RAM - 256 MB(min)

· Hard Disk - 20 GB

· Floppy Drive - 1.44 MB

· Key Board - Standard Windows Keyboard

· Mouse - Two or Three Button Mouse

· Monitor - SVGA

SOFTWARE REQUIREMENTS:-

· Operating System : Windows 7

· Front End : JSP AND SERVLET

· Database : MYSQL

· Tool :NETBEANS

REFERENCE

Wu, Q. Qin, B. Zhang, L. Domingo-Ferrer, J.“Contributory Broadcast Encryption With Efficient Encryption And Short Cipher Texts,” IEEE Transactions on Computers, Volume PP Issue 99, APRIL 2015.

A Computational Dynamic Trust Model for User Authorization

Abstract

Development of authorization mechanisms for secure information access by a large community of users in an open environment is an important problem in the ever-growing Internet world. In this paper we propose a computational dynamic trust model for user authorization, rooted in findings from social science. Unlike most existing computational trust models, this model distinguishes trusting belief in integrity from that in competence in different contexts and accounts for subjectivity in the evaluation of a particular trustee by different trusters. Simulation studies were conducted to compare the performance of the proposed integrity belief model with other trust models from the literature for different user behavior patterns. Experiments show that the proposed model achieves higher performance than other models especially in predicting the behavior of unstable users.

Aim

The main aim is to compute dynamic trust model for user authorization to secure information access by a large community of users in an open environment in the ever-growing Internet world.

Scope:

The scope is to enable automated trust management that mimics trusting behaviors, trusting belief in integrity from that in competence

Existing System

Social trust model defines five conceptual trust types:

1) trusting behavior,

2) trusting intention,

3) trusting belief,

4) institution-based trust,

5) disposition to trust.

Trusting behavior is an action that increases a truster's risk or makes the truster vulnerable to the trustee.

Trusting intention indicates that a truster is willing to engage in trusting behaviors with the trustee.

Trusting belief is a truster's subjective belief in the fact that a trustee has attributes beneficial to the truster. The following are the four attributes used most often: Competence, Benevolence, Integrity, Predictability

Institution-based trust is the belief that proper structural conditions are in place to enhance the probability of achieving a successful outcome.

Two subtypes of institution- based trust are: 1. Structural assurance 2. Situational normality.

Disposition to trust characterizes a truster's general propensity to depend on others across a broad spectrum of situations. Two subtypes of disposition to trust are: 1. Faith in human 2. Trusting stance

Trust intention and trusting belief are situation and trustee specific. Institution-based trust is situation specific. Disposition to trust is independent of situation and trustee. Trusting belief positively relates to trusting intention, which in turn results in the trusting behavior. Institution- based trust positively affects trusting belief and trusting intention. Structural assurance is more related to trusting intention while situational normality affects both. Disposition to trust positively influences institution-based trust, trusting belief and trusting intention. Faith in humanity impacts trusting belief. Trusting stance influences trusting intention.

The existing approaches are to extract reputation from the social network topology that encodes reputation information, for social networks, based on the concept of feedback centrality, for access control in P2P networks, based on the assumption of transitivity of trust in social networks, where a simple mathematical model based on fuzzy set membership is used to calculate the trustworthiness of each node in a trust graph symbolizing interactions between network nodes, for nodes in a P2P network, based on the history of interactions between nodes.

Disadvantages

Although the existing approaches integrate context into trust computation, their application is limited to specific domains.

Proposed System

In this paper we propose a computational dynamic trust model for user authorization, rooted in findings from social science. This model distinguishes trusting belief in integrity from that in competence in different contexts and accounts for subjectivity in the evaluation of a particular trustee by different trusters. The proposed model accounts for different types of trust. Specifically, it distinguishes trusting belief in integrity from that in competence. The model takes into account the subjectivity of trust ratings by different entities, and introduces a mechanism to eliminate the impact of subjectivity in reputation aggregation.

Advantages

The model evaluates trust separately for each property of each component of a platform.The proposed dynamic trust model enables automated trust management that mimics trusting behaviors in society, such as selecting a corporate partner, forming a coalition, or choosing negotiation protocols or strategies in e-commerce. The formalization of trust helps in designing algorithms to choose reliable resources in peer-to-peer systems, developing secure protocols for ad hoc networks and detecting deceptive agents in a virtual community. Experiments in a simulated trust environment show that the proposed integrity trust model performs better than other major trust models in predicting the behavior of users whose actions change based on certain patterns over time.

System Architecture