scholarly journals NON LINEAR FEEDBACK STREAM CIPHER

2012 ◽  
pp. 132-138
Author(s):  
Dr .R. Siva Ram Prasad ◽  
G. Murali ◽  
S. Gopi Krishna
Keyword(s):  
Linear Function ◽  
Stream Cipher ◽  
Nonlinear Function ◽  
Linear Feedback ◽  
Synchronous Mode ◽  
Plain Text ◽  
Cipher Text ◽  
Security Software ◽  
Non Linear ◽  
New Generation

The main aim of this paper is to develop a new generation and innovative security software for applications. We proposed new stream cipher called NLFS. NLFS means Non-linear feedback stream cipher, which is a fast and secure stream cipher for egovernance applications. This stream cipher uses AES secure non-linear function and AES key generation. NLFS uses primitive polynomial generated S-boxes in byte substitution step. NLFS uses two similar AES round functions and these two proceed parallelly to produce key-stream. Non-linear *function of NLFS has AES nonlinear function steps (add-round key, byte substitution, mix column, shift rows) and it extra includes value-based rotation step. In value based rotation step it rotates each 8-bit word by its first 3-bit (decimal) value.NLFS have two modes basic mode that is synchronous mode and self synchronous mode. In synchronous mode key stream is independent of plain text and cipher text. In selfsynchronous mode key stream generation depending on cipher text. In self synchronous mode generated keystream update first 512-bit buffer and cipher text update the second buffer.

scholarly journals Modifying LFSR of ZUC to Reduce Time for Key-Stream Generation

2017 ◽  
Author(s):  
Raja Muthalagu ◽  
Subeen Jain
Keyword(s):  
Linear Function ◽  
Stream Cipher ◽  
Linear Feedback ◽  
Initial Vector ◽  
Text Data ◽  
Cipher Text ◽  
Non Linear ◽  
Three Stages ◽  
Feedback Shift Register ◽  
Small Change

ZUC is stream-cipher which generates 32-bit key-stream by using 128-bit initial key and 123-bit initial vector. It encrypts the plaintext data to produce cipher-text data. The 128-EEA3 encryption and 128-EIA3 authentication algorithms are based on ZUC which are specified for use in 3GPP cellular communications systems. The algorithm is divided in three stages: LFSR (Linear Feedback Shift Register), Bit Reorganization (BR) and, Non-Linear Function. In this paper, we are going to discuss about our modifications proposed for LFSR along with small change in operation of Non-linear Function which can reduce time for generating key-stream. Many attacks based on weakness of LFSR due to its linearity are proposed which in turn makes ZUC susceptible to various attacks based on LFSR. As we know in the structure of LFSR, non-linearity is provided in last block of LFSR by feedback operation while all other being clocked with previous value of LFSR, so we have introduced bit-shifting and circular shift operations on few blocks of LFSR output of which will be taken as input to other blocks of LFSR.  

scholarly journals Enhancement of A5/1 Stream Cipher with Non-Linear Function using MOSFET

2019 ◽  
Vol 9 (1S3) ◽  
pp. 101-105
Keyword(s):  
Network Security ◽  
Linear Function ◽  
Stream Cipher ◽  
Security Threats ◽  
Computational Power ◽  
Secret Key ◽  
Non Linear ◽  
Gsm Network ◽  
Modern Era

Living in this modern era – the epitome of communication GSM networks is one of the mainly used architectures. But GSM architecture has its own shortcomings; the GSM network is vulnerable to various security threats. For any network to provide security to the user, the algorithms should be planned and designed in such a way that it provides cellular secrecy, data and signaling confidentiality to the concerned user. Keeping in mind the above features, the A5/1 algorithm provides network security. Initially, the A5/1 algorithm dealt with a pre-defined secret key but they still possess the threat of being decrypted by cryptanalytic attacks. Although decrypting this algorithm is not easy and requires high computational power. Such attacks lead to the necessity to modify the A5/1 algorithm; in our paper, we have proposed a better method to enhance the already existing algorithm.

scholarly journals Encryption and Decryption algorithm using two dimensional cellular automata rules in Cryptography

2011 ◽  
pp. 18-23
Author(s):  
Sambhu Prasad Panda ◽  
Madhusmita Sahu ◽  
Umesh Prasad Rout ◽  
Surendra Kumar Nanda
Keyword(s):  
Cellular Automata ◽  
Periodic Boundary ◽  
Block Cipher ◽  
Two Dimensional ◽  
Substitution Box ◽  
Plain Text ◽  
Cipher Text ◽  
Xor Operation ◽  
Encryption And Decryption ◽  
Non Linear

In this paper we present a new encryption and decryption algorithm for block cipher based on the linear (periodic boundary-PB) and nonlinear cellular automata rules. First we apply non linear CA rules (complements) to both plain text and key. Then PB CA rule is applied to the above results separately followed by the XOR operation of above results. After that the result of XOR operation is fed to substitution box(S-box) and again PB CA rules are applied followed by SBox. The decryption process is carried out just similar to that of encryption but in the reverse way. Both the process of encryption and decryption is performed for 8 number of rounds in order to avoid the dependency between the plain text and cipher text so that the our proposed algorithm is more secure than that of AES and DES algorithms.

scholarly journals Using Evolving Algorithms to Cryptanalysis Nonlinear Cryptosystems

2020 ◽  
Vol 17 (2(SI)) ◽  
pp. 0682
Author(s):  
Riyam Noori Jawad ◽  
Faez Hassan Ali
Keyword(s):  
Genetic Algorithm ◽  
Ant Colony Optimization ◽  
Stream Cipher ◽  
Optimal Solution ◽  
Shift Register ◽  
Linear Feedback ◽  
Cipher Text ◽  
Initial Values ◽  
Weak Points ◽  
Feedback Shift Register

            In this paper, new method have been investigated using evolving algorithms (EA's) to cryptanalysis one of the nonlinear stream cipher cryptosystems which depends on the Linear Feedback Shift Register (LFSR) unit by using cipher text-only attack. Genetic Algorithm (GA) and Ant Colony Optimization (ACO) which are used for attacking one of the nonlinear cryptosystems called "shrinking generator" using different lengths of cipher text and different lengths of combined LFSRs. GA and ACO proved their good performance in finding the initial values of the combined LFSRs. This work can be considered as a warning for a stream cipher designer to avoid the weak points, which may be found in the stream cipher, and may be explored by the cryptanalysts. This work can find the optimal solution for text with minimum lengths of 20 characters and 100 iteration were very enough to find the real initial values of key stream.

scholarly journals Novel Method Using Crossover (Genetic Algorithms) With Matrix Technique to Modifying Ciphering by Using Playfair

2013 ◽  
Vol 6 (3) ◽  
pp. 97-106
Author(s):  
Mohammed Sami Mohammed
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
The Other ◽  
Plain Text ◽  
Cipher Text ◽  
One Step ◽  
Novel Method ◽  
Get Complex ◽  
New Generation

Two techniques combined with each other, to get complex one. One from technique of genetic algorithm (GA) and the other is PlayFair cipher method, in this research using one step of Genetic Algorithm (GA) which called Crossover to make offspring of two parents (characters) to get one or two new character by using these techniques then using PlayFair technique to cipher text (plain text). So the person who wants to break code, two techniques must know.This research is a novel method of ciphering by getting a new generation of offspring from two characters, when we give a new theory of symbols as mention in research.

scholarly journals How to make a kin selection model when marginal fitness is non-linear?

2014 ◽  
Author(s):  
Roberto H. Schonmann ◽  
Robert Boyd ◽  
Renato Vicente
Keyword(s):  
Linear Function ◽  
Social Environment ◽  
Kin Selection ◽  
Mutant Allele ◽  
Nonlinear Function ◽  
Selection Model ◽  
Fitness Functions ◽  
Non Linear ◽  
Monomorphic Population ◽  
Function Of Two Variables

We observe that the Taylor-Frank method for making kin selection models when fitness $w$ is a nonlinear function of a continuous actor's phenotype $y$ and the average phenotype $z$ in its social environment requires $w(y,z)$ to be differentiable (as a function of two variables, i.e., jointly in $y$ and $z$). This means that even if $w(y,z)$ is non-linear globally, locally it must be close to linear, meaning that its graph must be well approximated by a plane. When more than two individuals interact, this assumption is only satisfied when the marginal fitness of the actor is a linear function of the fraction of individuals in its social environment that share its phenotype. This assumption sometimes fails for biologically important fitness functions, for instance in microbial data and the theory of repeated n-person games. In these cases, the Taylor-Frank methodology cannot be used, and a more general form of direct fitness must replace it, to decide when a social mutant allele can invade a monomorphic population.

CLASS OF BOOLEAN FUNCTIONS CONSTRUCTED USING SIGNIFICANT BITS OF LINEAR RECURRENCES OVER THE RING ℤ2n

2019 ◽  
Vol 6 (2) ◽  
pp. 90-94
Author(s):  
Hernandez Piloto Daniel Humberto
Keyword(s):  
Linear Function ◽  
Boolean Functions ◽  
Hamming Distance ◽  
Linear Recurrences ◽  
Maximum Period ◽  
Non Linear ◽  
The Given ◽  
Class Of Functions

In this work a class of functions is studied, which are built with the help of significant bits sequences on the ring ℤ2n. This class is built with use of a function ψ: ℤ2n → ℤ2. In public literature there are works in which ψ is a linear function. Here we will use a non-linear ψ function for this set. It is known that the period of a polynomial F in the ring ℤ2n is equal to T(mod 2)2α, where α∈ , n01- . The polynomials for which it is true that T(F) = T(F mod 2), in other words α = 0, are called marked polynomials. For our class we are going to use a polynomial with a maximum period as the characteristic polyomial. In the present work we show the bounds of the given class: non-linearity, the weight of the functions, the Hamming distance between functions. The Hamming distance between these functions and functions of other known classes is also given.

Comparative Study of Cryptography for Cloud Computing for Data Security

2019 ◽  
Vol 13 ◽  
Author(s):  
Priya Mathur ◽  
Amit Kumar Gupta ◽  
Prateek Vashishtha
Keyword(s):  
Cloud Computing ◽  
Data Security ◽  
Elliptic Curve Cryptography ◽  
Plain Text ◽  
Hybrid Encryption ◽  
Cipher Text ◽  
Business Applications ◽  
Computing Grid ◽  
Cloud Servers ◽  
Client Side

Cloud computing is an emerging technique by which anyone can access the applications as utilities over the internet. Cloud computing is the technology which comprises of all the characteristics of the technologies like distributed computing, grid computing, and ubiquitous computing. Cloud computing allows everyone to create, to configure as well as to customize the business applications online. Cryptography is the technique which is use to convert the plain text into cipher text using various encryption techniques. The art and science used to introduce the secrecy in the information security in order to secure the messages is defined as cryptography. In this paper we are going to review few latest Cryptographic algorithms which are used to enhance the security of the data on the cloud servers. We are comparing Short Range Natural Number Modified RSA (SRNN), Elliptic Curve Cryptography Algorithm, Client Side Encryption Technique and Hybrid Encryption Technique to secure the data in cloud.

Sign in / Sign up

Export Citation Format

Share Document