Security Issues and Solutions in Multicast Environment through Tree based Scheme

Multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source creating copies automatically in other network elements, such as routers, only when the topology of the network requires it. Multicasting security is hard because of Open group membership, everyone gets same pack ets, Senders need not be members. We first present taxonomy of mu lticast scenarios on the Internet and point out relevant security concerns. Next we address two major security problems of multicast communication: source authentication, and key revocation. Maintaining authenticity in multicast protocols is a much more complex problem than for unicast, in particular known solutions are prohibitively inefficient in many cases. We present a solution that is reasonable for a range of scenarios. Our approach can be regarded as a midpoi nt between traditional Message Authentication Codes and digital signatures. We also present an improved solution to the key revocation problem

Secure Data Storage on Cloud through Networking

Security, privacy issue and data protection is always one of the major issue which reduces the growth and make slow the speed of rising new technologies in the field of cloud computing. The advent of an advanced model should not negotiate with the required functionalities and capabilities present in the current model. Here to avoid risk and threaten are reduced in the new model the features are improved. In this paper, a survey of the different security risks that pose a threat to the cloud is presented. This paper is a survey more specific to the different security issues that has emanated due to the nature of the service delivery models of a cloud computing system

Multi-Channel Security through Data Fragmentation

This thesis presents a novel security system developed for a multi-channel communication architecture, which achieves security by distributing the message and its associated message authentication code across the available channels at the bit level, to support systems that require protection from confidentiality and integrity attacks without relying solely on traditional encryption. One contribution of the work is to establish some helpful terminology, present a basic theory for multi-channel communications, describe the services provided by an optimal system, and then implement a proof of concept system to demonstrate the concept\u27s validity. This proof of concept, focused on the splitting and recombination activities, operates by using existing key exchange mechanisms to establish system initialization information, and then splitting the message in fragments across each available channel. Splitting prevents the entirety of a given message from being transmitted across a single channel, and spreads the overall message authentication across the set of channels. This gives the end user the following unique service: the sender and receiver can identify a compromised channel, even in the presence of a sophisticated man in the middle attack wherein the adversary achieves fragment acceptance at the destination by altering the message\u27s error detecting code. Under some conditions, the receiver can recover the original message without retransmission, despite these injected errors. The resulting system may be attractive for critical infrastructure communications systems as a holistic approach to both availability and a defense against integrity attacks. This system would be a natural fit as a cipher suite for a future iteration of the Transport Layer Security protocol targeting support for multi-channel communication systems

CONSTRUCTION OF EFFICIENT AUTHENTICATION SCHEMES USING TRAPDOOR HASH FUNCTIONS

In large-scale distributed systems, where adversarial attacks can have widespread impact, authentication provides protection from threats involving impersonation of entities and tampering of data. Practical solutions to authentication problems in distributed systems must meet specific constraints of the target system, and provide a reasonable balance between security and cost. The goal of this dissertation is to address the problem of building practical and efficient authentication mechanisms to secure distributed applications. This dissertation presents techniques to construct efficient digital signature schemes using trapdoor hash functions for various distributed applications. Trapdoor hash functions are collision-resistant hash functions associated with a secret trapdoor key that allows the key-holder to find collisions between hashes of different messages. The main contributions of this dissertation are as follows: 1. A common problem with conventional trapdoor hash functions is that revealing a collision producing message pair allows an entity to compute additional collisions without knowledge of the trapdoor key. To overcome this problem, we design an efficient trapdoor hash function that prevents all entities except the trapdoor key-holder from computing collisions regardless of whether collision producing message pairs are revealed by the key-holder. 2. We design a technique to construct efficient proxy signatures using trapdoor hash functions to authenticate and authorize agents acting on behalf of users in agent-based computing systems. Our technique provides agent authentication, assurance of agreement between delegator and agent, security without relying on secure communication channels and control over an agent’s capabilities. 3. We develop a trapdoor hash-based signature amortization technique for authenticating real-time, delay-sensitive streams. Our technique provides independent verifiability of blocks comprising a stream, minimizes sender-side and receiver-side delays, minimizes communication overhead, and avoids transmission of redundant information. 4. We demonstrate the practical efficacy of our trapdoor hash-based techniques for signature amortization and proxy signature construction by presenting discrete log-based instantiations of the generic techniques that are efficient to compute, and produce short signatures. Our detailed performance analyses demonstrate that the proposed schemes outperform existing schemes in computation cost and signature size. We also present proofs for security of the proposed discrete-log based instantiations against forgery attacks under the discrete-log assumption

Challenges of Implementing Automatic Dependent Surveillance Broadcast in the Nextgen Air Traffic Management System

The Federal Aviation Administration is in the process of replacing the current Air Traffic Management (ATM) system with a new system known as NextGen. Automatic Dependent Surveillance-Broadcast (ADS-B) is the aircraft surveillance protocol currently being introduced as a part of the NextGen system deployment. The evolution of ADS-B spans more than two decades, with development focused primarily on increasing the capacity of the Air Traffic Control (ATC) system and reducing operational costs. Security of the ADS-B communications network has not been a high priority, and the inherent lack of security measures in the ADS-B protocol has come under increasing scrutiny as the NextGen ADS-B implementation deadline draws near. The research conducted in this thesis summarizes the ADS-B security vulnerabilities that have been under recent study. Thereafter, we survey both the theoretical and practical efforts which have been conducted concerning these issues, and review possible security solutions. We create a classification of the ADS-B security solutions considered and provide a ranking of the potential solutions. Finally, we discuss the most compatible approaches available, given the constraints of the current ADS-B communications system and protocol