THE DYNAMIC CIPHERS – NEW CONCEPT OF LONG-TERM CONTENT PROTECTING

In the paper the original concept of a new cipher, targeted at this moment forcivil applications in technology (e.g. measurement and control systems) and business (e.g.content protecting, knowledge-based companies or long-term archiving systems) is presented.The idea of the cipher is based on one-time pads and linear feedback shift registers. Therapidly changing hardware and software environment of cryptographic systems has beentaken into account during the construction of the cipher. The main idea of this work is tocreate a cryptosystem that can protect content or data for a long time, even more than onehundred years. The proposed algorithm can also simulate a stream cipher which makes itpossible to apply it in digital signal processing systems such as those within audio and videodelivery or telecommunication.Content protection, Cryptosystem, Dynamic cryptography, Linear Feedback ShiftRegisters, Object-oriented programming, One-time pad, Random key, random number generators,Statistical evaluation of ciphers.

Grein. A New Non-Linear Cryptoprimitive

In this thesis, we will study a new stream cipher, Grein, and a new cryptoprimitive used in this cipher. The second chapter gives a brief introduction to cryptography in general. The third chapter looks at stream ciphers in general, and explains the advantages and disadvantages of stream ciphers compared to block ciphers. In the fourth chapter the most important building blocks used in stream ciphers are explained. The reader is excepted to know elementary abstract algebra, as much of the results in this chapter depend on it. In the fifth chapter, the stream cipher Grain is introduced. In chapter six, the new stream cipher, Grein, is introduced. Here, we look at the different components used in the cipher, and how they operate together. In chapter seven, we introduce an alteration to the Grein cryptosystem, which hopefully have some advantagesMaster i InformatikkMAMN-INFINF39

A Spatiotemporal-chaos-based Encryption Having Overall Properties Considerably Better Than Advanced Encryption Standard

Spatiotemporal chaos of a two-dimensional one-way coupled map lattice is used for chaotic cryptography. The chaotic outputs of many space units are used for encryption simultaneously. This system shows satisfactory cryptographic properties of high security; fast encryption (decryption) speed; and robustness against noise disturbances in communication channel. The overall features of this spatiotemporal-chaos-based cryptosystem are better than chaotic cryptosystems known so far, and also than currently used conventional cryptosystems, such as the Advanced Encryption Standard (AES).Comment: 11 pages, 3 figure

Some New Mathematical Tools in Cryptology

In this paper some new mathematical technique used in the design and analysis of cipher systems have been reviewed. Firstly, some modern cryptosystems like stream ciphers, permutation-based systems and public key encryption systems are described and the mathematical tools used in their design have been outlined. Special emphasis has been laid on the problems related to application of computational complexity to cryptosystems. Recent work on the design of the systems based on a combined encryption and coding for error correction has also been reviewed. Some recent system-oriented techniques of cryptanalysis have been discussed. It has been brought out that with the increase in the complexity of the cryptosystems it is necessary to apply some statistical and classification techniques for the purpose of identifying a cryptosystem as also for classification of the total key set into smaller classes. Finally, some very recent work on the application of artificial intelligence technique in cryptography and cryptanalysis has been mentioned

An Efficient VLSI Architecture for Rivest-Shamir-Adleman Public-key Cryptosystem

[[abstract]]In this paper, a new efficient VLSI architecture to compute modular exponentiation and modular multiplication for Rivest-Shamir-Adleman (RSA) public-key cryptosystem is proposed. We modify the conventional H-algorithm to find the modular exponentiation. By this modified H-algorithm, the modular multiplication steps for n-bit numbers are reduced by 5n/18 times. For the modular multiplication a modified L-algorithm (LSB first) is used. In the architecture of the modified modular multiplication the iteration times are only half of Montgomery's algorithm and the H-algorithm. The proposed architecture for the RSA public-key crypto-system has a data rate of 146 kb/s for 512-b words with a 200-MHz clock rate.[[notice]]補正完

Quantum Algorithms for Some Hidden Shift Problems

Almost all of the most successful quantum algorithms discovered to date exploit the ability of the Fourier transform to recover subgroup structures of functions, especially periodicity. The fact that Fourier transforms can also be used to capture shift structure has received far less attention in the context of quantum computation. In this paper, we present three examples of "unknown shift" problems that can be solved efficiently on a quantum computer using the quantum Fourier transform. For one of these problems, the shifted Legendre symbol problem, we give evidence that the problem is hard to solve classically, by showing a reduction from breaking algebraically homomorphic cryptosystems. We also define the hidden coset problem, which generalizes the hidden shift problem and the hidden subgroup problem. This framework provides a unified way of viewing the ability of the Fourier transform to capture subgroup and shift structure