scholarly journals Generalization of the Self-Shrinking Generator in the Galois Field

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Antoniya Todorova Tasheva ◽  
Zhaneta Nikolova Tasheva ◽  
Aleksandar Petrov Milev
Keyword(s):  
Hardware Implementation ◽  
Stream Cipher ◽  
Low Cost ◽  
Binary Sequence ◽  
Galois Field ◽  
The Self ◽  
Security Requirements ◽  
Linear Feedback ◽  
Large Period ◽  
Feedback Shift Register

The proposed by Meier and Staffelbach Self-Shrinking Generator (SSG) which has efficient hardware implementation only with a single Linear Feedback Shift Register is suitable for low-cost and fast stream cipher applications. In this paper we generalize the idea of the SSG for arbitrary Galois Field . The proposed variant of the SSG is called the -ary Generalized Self-Shrinking Generator (pGSSG). We suggest a method for transformation of a non-binary self-shrunken pGSSG sequence into balanced binary sequence. We prove that the keystreams of the pGSSG have large period and good statistical properties. The analysis of the experimental results shows that the pGSSG sequences have good randomness properties. We examine the complexity of exhaustive search and entropy attacks of the pGSSG. We show that the pGSSG is more secure than SSG and Modified SSG against these attacks. We prove that the complexity of the used pGSSG attacks increases with increasing the prime . Previously mentioned properties give the reason to say that the pGSSG satisfy the basic security requirements for a stream chipper and can be useful as a part of modern stream ciphers.

Fuzzy Logic-Based Security Evaluation of Stream Cipher

2015 ◽  
pp. 277-298 ◽  
Author(s):  
Sattar B. Sadkhan Al Maliky ◽  
Sabiha F. Jawad
Keyword(s):  
Fuzzy Logic ◽  
Stream Cipher ◽  
Evaluation Method ◽  
Shift Register ◽  
Fuzzy Rules ◽  
Linear Feedback Shift Register ◽  
Linear Feedback ◽  
Security Evaluation ◽  
Maximum Period ◽  
Feedback Shift Register

The main aim of this chapter is to provide a security evaluation method based on fuzzy logic “for a pseudo-random sequences used (mainly) in stream cipher systems. The designed Fuzzy rules consider two main parameters, which are the length of the maximum period of the key sequence obtained from Linear Feedback Shift Register (LFSR) and the entropy of the result in sequences obtained from different lengths of the shift registers. The security (complexity) evaluation method is applied to the summation generator (a type of non-linear feedback shift register) in this chapter. First it is applied to its original well-known form (with one bit memory); then the evaluation method is applied to the developed summation generator (by varying the number of the delayed bits by two and by three bits). The acceptability of the results of developed evaluation method indicates a goodness of such developed approach in the security evaluation.

scholarly journals Security analysis of linearly filtered NLFSRs

2013 ◽  
Vol 7 (4) ◽  
pp. 313-332 ◽  
Author(s):  
Mohammad Ali Orumiehchiha ◽  
Josef Pieprzyk ◽  
Ron Steinfeld ◽  
Harry Bartlett
Keyword(s):  
Linear Combination ◽  
Mobile Communication ◽  
Stream Cipher ◽  
High Efficiency ◽  
Security Analysis ◽  
Linear Feedback ◽  
Attractive Feature ◽  
Key Recovery ◽  
Distinguishing Attack ◽  
Feedback Shift Register

Abstract. Non-linear feedback shift register (NLFSR) ciphers are cryptographic tools of choice of the industry especially for mobile communication. Their attractive feature is a high efficiency when implemented in hardware or software. However, the main problem of NLFSR ciphers is that their security is still not well investigated. The paper makes a progress in the study of the security of NLFSR ciphers. In particular, we show a distinguishing attack on linearly filtered NLFSR (or LF-NLFSR) ciphers. We extend the attack to a linear combination of LF-NLFSRs. We investigate the security of a modified version of the Grain stream cipher and show its vulnerability to both key recovery and distinguishing attacks.

scholarly journals Scrambling and De-Scrambling Implementation Using Linear Feedback Shift Register Method on FPGA

2017 ◽  
Vol 1 (02) ◽  
pp. 59-67
Author(s):  
Manda Lurina ◽  
Sugondo Hadiyoso ◽  
Rina Pudji Astuti
Keyword(s):  
Binary Sequence ◽  
Logic Gates ◽  
Shift Register ◽  
Linear Feedback Shift Register ◽  
Linear Feedback ◽  
False Detection ◽  
System A ◽  
Feedback Shift Register ◽  
Original Information ◽  
Randomization Process

communication system, a long sequence of bits ‘0’ or ‘1’ will inherits the loss of bit synchronization, and hence it can cause the false detection on the receiver. To avoid this, long sequence of bits will be randomized first so that long sequence of bits ‘0’ or ‘1’ can be removed. This randomization process is called scrambling and the circuit that works for the process is a scrambler. In the receiver there is a descrambler that serves to return the bits to their original information. This paper presents a design of scrambler and descrambler using a combination of Linear Feedback Shift Register (LFSR) with 15 registers, XOR logic gates, and Pseudo Random Binary Sequence (PRBS) generator structure with polynomial 1 + x14 + x15. One of the two main parts of LFSR is the shift register while the other is the feedback. In LFSR, the bits contained within the selected position in the shift register will be combined in a function and the result will be put back into this register's input bit. Feedback also makes the system more stable and no error occurrence. Then special tap is taken from a certain point in XOR and returned as a feedback register. The system is implemented on FPGA board Altera De0-Nano EP4CE22F17C6 Cyclone IV E. Resource memory required <1% of available memory. Bit rate that can be achieved with clock speed 50MHz is 335570.47 bps.

scholarly journals Generating a Strong Key for a Stream Cipher Systems Based on Permutation Networks

2007 ◽  
Vol 4 (3) ◽  
pp. 501-504
Author(s):  
Baghdad Science Journal
Keyword(s):  
Communication Systems ◽  
Stream Cipher ◽  
Linear Feedback ◽  
High Complexity ◽  
Long Period ◽  
Auto Correlation ◽  
Crossbar Switches ◽  
Feedback Shift Register ◽  
Pn Sequences ◽  
Randomness Tests

The choice of binary Pseudonoise (PN) sequences with specific properties, having long period high complexity, randomness, minimum cross and auto- correlation which are essential for some communication systems. In this research a nonlinear PN generator is introduced . It consists of a combination of basic components like Linear Feedback Shift Register (LFSR), ?-element which is a type of RxR crossbar switches. The period and complexity of a sequence which are generated by the proposed generator are computed and the randomness properties of these sequences are measured by well-known randomness tests.

Color Image Encryption Scheme Based on Chaotic Map

2012 ◽  
Vol 182-183 ◽  
pp. 1800-1804
Author(s):  
Jin Qiu ◽  
Ping Wang
Keyword(s):  
Image Encryption ◽  
Stream Cipher ◽  
Color Image ◽  
Statistical Tests ◽  
Chaotic Map ◽  
Linear Feedback ◽  
Encryption Scheme ◽  
Color Image Encryption ◽  
Overall Design ◽  
Feedback Shift Register

In this paper, a chaos-based image encryption scheme with stream cipher structure is proposed. The key component of the encryption system is a pseudo-random bit generator (PRBG) based on a chaotic map and a linear feedback shift register. The proposed PRBG is not only passes the statistical tests, but also improve the security. The overall design of the image encryption scheme is to be explained while detail cryptanalysis is given.

Fuzzy Logic-Based Security Evaluation of Stream Cipher

2014 ◽  
pp. 157-178 ◽  
Author(s):  
Sattar B. Sadkhan Al Maliky ◽  
Sabiha F. Jawad
Keyword(s):  
Fuzzy Logic ◽  
Stream Cipher ◽  
Evaluation Method ◽  
Shift Register ◽  
Fuzzy Rules ◽  
Linear Feedback Shift Register ◽  
Linear Feedback ◽  
Security Evaluation ◽  
Maximum Period ◽  
Feedback Shift Register

The main aim of this chapter is to provide a security evaluation method based on fuzzy logic “for a pseudo-random sequences used (mainly) in stream cipher systems. The designed Fuzzy rules consider two main parameters, which are the length of the maximum period of the key sequence obtained from Linear Feedback Shift Register (LFSR) and the entropy of the result in sequences obtained from different lengths of the shift registers. The security (complexity) evaluation method is applied to the summation generator (a type of non-linear feedback shift register) in this chapter. First it is applied to its original well-known form (with one bit memory); then the evaluation method is applied to the developed summation generator (by varying the number of the delayed bits by two and by three bits). The acceptability of the results of developed evaluation method indicates a goodness of such developed approach in the security evaluation.

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 Analysis Randomness Properties of Basic Components of SNOW 3G Cipher in Mobile Systems

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Khalid Fadhil Jasim ◽  
Imad Fakhri Al-Shaikhli
Keyword(s):  
Finite State Machine ◽  
Stream Cipher ◽  
Statistical Tests ◽  
Mobile Systems ◽  
Linear Feedback ◽  
Mobile Phone Technology ◽  
Finite State ◽  
Feedback Shift Register ◽  
Test Suit ◽  
Randomness Tests

Abstract— SNOW 3G is a stream cipher algorithm used as encryption algorithm in third generation mobile phone technology (3G-UMTS). In this paper, we analyzed and evaluated the randomness properties of basic components of SNOW 3G cipher. NIST test suit (SP 800-22) used in evaluating and testing the randomness properties. We conducted statistical tests on various components of SNOW 3G cipher such as keystream, Finite State Machine, S-boxes S1 and S2, registers (R1, R2,  and R3), and Linear Feedback Shift Register. Our experimental results and empirical analysis shown that SNOW 3G cipher passed statistical randomness tests.

scholarly journals A New Approach to the Development of Additive Fibonacci Generators Based on Prime Numbers

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2912
Author(s):  
Volodymyr Maksymovych ◽  
Oleh Harasymchuk ◽  
Mikolaj Karpinski ◽  
Mariia Shabatura ◽  
Daniel Jancarczyk ◽  
...  
Keyword(s):  
High Performance ◽  
Hardware Implementation ◽  
Pulse Sequence ◽  
Prime Numbers ◽  
Statistical Characteristics ◽  
Linear Feedback ◽  
Repetition Period ◽  
New Approach ◽  
Feedback Shift Register ◽  
Initial Settings

Pseudorandom number and bit sequence generators are widely used in cybersecurity, measurement, and other technology fields. A special place among such generators is occupied by additive Fibonacci generators (AFG). By itself, such a generator is not cryptographically strong. Nevertheless, when used as a primary it can be quite resistant to cryptanalysis generators. This paper proposes a modification to AGF, the essence of which is to use prime numbers as modules of recurrent equations describing the operation of generators. This modification made it possible to ensure the constancy of the repetition period of the output pseudorandom pulse sequence in the entire range of possible values of the initial settings–keys (seed) at specific values of the module. In addition, it has proposed a new generator scheme, which consists of two generators: the first of which is based on a modified AFG and the second is based on a linear feedback shift register (LFSR). The output pulses of both generators are combined through a logic element XOR. The results of the experiment show that the specific values of modules provide a constant repetition period of the output pseudorandom pulse sequence in a whole range of possible values of the initial settings–keys (seed) and provide all the requirements of the NIST test to statistical characteristics of the sequence. Modified AFGs are designed primarily for hardware implementation, which allows them to provide high performance.

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