M. Sethumadhavan

Novel mutual authentication protocol for cloud computing using secret sharing and steganography

Proper authentication is an essential technology for cloud-computing environments in which connections to external environments are common and risks are high. Here, a new scheme is proposed for mutual authentication where the user and cloud server can authenticate one another. The protocol is designed in such a way that it uses steganography as an additional encryption scheme. The scheme achieves authentication using secret sharing. Secret sharing allows a part of the secret to be kept in both sides which when combined becomes the complete secret. The secret contains information about both parties involved. Further, out of band authentication has been used which provides additional security. The proposed protocol provides mutual authentication and session key establishment between the users and the cloud server. Also, the users have been given the flexibility to change the password. Furthermore, strong security features makes the protocol well suited for the cloud environment.

Visual cryptographic schemes using combined Boolean operations

Abstract Visual Cryptographic scheme (VCS) is a variant form of secret sharing method to encode a secret image into n distinct shares. The dealer distributes shares to each participants in such a way that, while certain qualified subsets of participants can visually recover the secret, but other forbidden sets of participants have no information on the secret. Such a system is the general access structures in VCS. The essential access structure (k, n)* is a type of threshold scheme were one participant is the leader who holds the essential share and the remaining n-1 shares are given to n-1 participants. The secret image cannot be retrieved in the absence of leader and the leader needs the support of at least k-1 remaining participants to recover the secret image. Small pixel expansion and maximum contrast are the basic parameters for measuring the quality of the VCS. In the literature there are constructions for both deterministic and probabilistic (k, n)*-VCS. The following are the important contributions of this paper. (1) A deterministic (k, n)*-VCS with improved contrast. (2) A deterministic (k, n)- VCS for t essential participants with improved contrast and less pixel expansion. (3) An ideal contrast general access structure construction with AND operation for grey scale images. (4) An ideal contrast (k, n)*-VCS construction for both binary and grey scale images. (5) An ideal contrast (k, n)-VCS for t essential participants for both binary and grey scale images.

Survey of consensus protocols on blockchain applications

Blockchain is a distributed, transparent, immutable ledger. Consensus protocol forms the core of blockchain. They decide how a blockchain works. With the advent of new possibilities in blockchain technology, researchers are keen to find a well-optimized Byzantine fault tolerant consensus protocol. Creating a global consensus protocol or tailoring a cross-platform plug and play software application for implementation of various consensus protocols are ideas of huge interest. Stellar Consensus Protocol (SCP) is considered to be a global consensus protocol and promises to be Byzantine Fault Tolerant (BFT) by bringing with it the concept of quorum slices and federated byzantine fault tolerance. This consensuss working and its comparison with other protocols that were earlier proposed are analyzed here. Also, hyperledger an open-source project by Linux Foundation which includes implementing the concept of practical byzantine fault tolerance and also a platform where various other consensus protocols and blockchain applications can be deployed in a plug and play manner is also being discussed here. This paper focuses on analyzing these consensus protocols already proposed and their feasibility and efficiency in meeting the characteristics they propose to provide.

Hash-One: a lightweight cryptographic hash function

The increased demand for lightweight applications has triggered the need for appropriate security mechanisms in them. Lightweight cryptographic hash functions are among the major responses toward such a requirement. The authors thus have a handful of such hash functions such as QUARK, PHOTON, SPONGENT and GLUON introduced already. The cryptanalysis of these hash functions is crucial in analysing their strength and often calls for improvement in designs. Their performance, are also to be taken care of, in terms of both software and hardware implementations. Here, they propose a lightweight hash function with reduced complexity in terms of hardware implementation, capable of achieving standard security. It uses sponge construction with permutation function involving the update of two non-linear feedback shift registers. Thus, in terms of sponge capacity it provides at least 80 bit security against generic attacks which is acceptable currently.

Cyber Security, Cyber Crime and Cyber Forensics: Applications and Perspectives

By reading, you can know the knowledge and things more, not only about what you get from people to people. Book will be more trusted. As this cyber security cyber crime and cyber forensics applications and perspectives, it will really give you the good idea to be successful. It is not only for you to be success in certain life you can be successful in everything. The success can be started by knowing the basic knowledge and do actions.

Cube Attack on Stream Ciphers using a Modified Linearity Test

Abstract There have been various attempts to attack reduced variants of Trivium stream cipher using cube attack. During the preprocessing phase of cube attack, we need to test the linearity of a superpoly. The linearity testing problem is to check whether a function is close to linear by asking oracle queries to the function. This is the BLR linearity test for Boolean functions, which has a time complexity of O(22k + c) cipher operations, where k is the length of the key and c is the size of the cube. In this paper we present a method which is supposed to be a sufficient condition for testing a superpoly for linearity in F2 with a time complexity O(2c + 1 (k2 + k)). Our analysis on Trivium cipher reduced to 576 rounds using cube attack gives 69 extremely sparse linearly independent linear equations for smaller cubes, which recovers 69 bits of the key and reduces the attack complexity in the online phase to 211.

On the Extensions of (k, n)*-Visual Cryptographic Schemes

A deterministic (k, n)*-Visual cryptographic scheme (VCS) was proposed by Arumugam et.al [1] in 2012. Probabilistic schemes are used in visual cryptography to reduce the pixel expansion. In this paper, we have shown that the contrast of probabilistic (k, n)*-VCS is same as that of deterministic (k, n)*- VCS. This paper also proposes a construction of (k, n)*-VCS with multiple essential participants. It is shown that in both deterministic and probabilistic cases the contrast of the (k, n)*-VCS with multiple essential participant is same as that of (k, n)*-VCS.

A construction of p-ary balanced sequence with large k-error linear complexity

Abstract In this paper we derive a result on the k-error linear complexity of balanced p-ary sequences of period N=p n . Using this result, we also describe a construction of a sequence having large linear complexity. These results are of relevance in the construction of key sequences for stream ciphers.

Ideal Contrast Visual Cryptography for General Access Structures with AND Operation

In Visual Cryptographic Scheme (VCS) reversing operations (NOT operations) are carried out during reconstruction process to improve the quality of the reconstructed secret image. Many studies were reported on using reversing operation in both perfect and nonperfect black VCS. In 2005, Cimato et al. put forward an ideal contrast VCS with reversing, which is applicable to any access structures (IC-GA-VCS). Here there will not be any change in resolution for reconstructed secret image in comparison with original secret image (KI). In this paper a proposal for replacing reversing operations with AND operations during reconstruction in perfect black VCS is shown. A comparison of the proposed modification with Cimato et al. construction and other related work are discussed in this paper.

A Framework for Analysing the Security of Chrome Extensions

Google Chrome, the most popular web browser today, allows users to extend its functionality by means of extensions available in its own store or any third party website. Users can also develop their own extensions easily and add them to their browser. Vulnerabilities in browser extensions could be exploited by malicious websites to gain access to sensitive user data or to attack another website. A browser extension can also turn malicious and attack a website or steal user data. This paper proposes a framework which can be used by users and developers to analyse Chrome extensions. The technique presented here uses the permissions feature of chrome extensions and the flow of data through the extension’s JavaScript code to detect vulnerabilities in extensions and to check whether the extension could be malicious.