Size Of Plaintext Research Articles

Micro Rotor Enhanced Block Cipher Designed For Eight Bits Micro-Controllers (MREBC)

The sensor network is a wireless network environment that consists of the many sensors of lightweight and low-power. Authentication between nodes is very vital for network reliability and the integrity of information collected by these nodes. Therefore, encryption algorithm for the implementation of reliable sensor network environments is required to the applicable sensor network. This paper gives a new proposed cryptosystem (MREBC) that is designed for 8 bits microcontroller systems. MREBC uses the concept of rotor enhanced block cipher which was initially proposed by the author in [NRSC 2002] on the first version of REBC. MREBC uses rotors to achieve two basic cryptographic operations; permutation, and substitution. Round key is generated using rotor too, which is used to achieve ciphertext key dependency. Rotors implemented using 8 bits successive affine transformation, which achieves memoryless, normalized ciphertext statistics, and small processing speed trend. The strength of this system is compared with the RIJNDAEL (AES) cipher. MREBC cipher gives excellent results from security characteristics and statistical point of view of. communication efficiency of MREBC is compared with AES through measuring performance by plaintext size, and cost of operation per hop according to the network scale. Arduino microcontroller board is used to implement both MREBC, and AES in order to compare the performance of algorithms. Authors suggests to use MREBC to implement a reliable sensor network environments.

A Simple Algebraic Model based Polyalphabetic Substitution Cipher

ABSTRACT Cryptography is considered to be a disciple of science of achieving security by converting sensitive information to an un-interpretable form such that it cannot be interpreted by anyone except the transmitter and intended recipient. An innumerable set of cryptographic schemes persist in which each of it has its own affirmative and feeble characteristics. In this paper we have we have developed a traditional or character oriented Polyalphabetic cipher by using a simple algebraic equation. In this we made use of iteration process and introduced a key K 0 obtained by permuting the elements of a given key seed value. This key strengthens the cipher and it does not allow the cipher to be broken by the known plain text attack. The cryptanalysis performed clearly indicates that the cipher is a strong one. . Keywords Polyalphabetic substitution, variable length key stream, bit-ratio test, frequency test. 1. INTRODUCTION Cryptography is considered to be a collection of tools and techniques related to components of information security such as confidentiality, authenticity, integrity, non-repudiation [1]. Cryptography refers to the science of securing data by changing the data into non-interpretable form, cryptanalysis is the science of analyzing and breaking secure communication. Cryptanalyst or attacker is a person who performs cryptanalysis [2]. Cryptology is a combination of both cryptography and cryptanalysis. A no of cryptanalytic attacks can be found wherein cipher text only, known plaintext, chosen plaintext, chosen cipher text, adaptive chosen plaintext, brute force attack, key guessing attack etc are to name a few [3]. In this paper we propose a simple algebraic model based Polyalphabetic substitution cipher wherein the plain text is converted to cipher text by the use of a key-seed value from which variable length key stream is generated producing different cipher text with every run time for similar entered plain text. In section 2 we have presented the basic terminologies. Section 3 depicts the proposed algorithm both for encryption and decryption. In section 4 we have presented the experimental results. Testing and analysis is given in section 5 comprising of frequency distribution test, bit-ratio test, encryption and decryption time comparison and comparison of plain text size with cipher file size. On the basis of testing and analysis performed conclusions are drawn in section 6.

동적 네트워크를 이용한 대칭블록암호 알고리즘

동적 암호는 키의 크기, 라운드의 수 그리고 평문의 크기가 동시에 측정될 수 있는 특성을 갖고 있다. 본 논문에서는 동적 네트워크에 기반한 대칭적인 블록 암호 알고리즘을 제안한다. 제안하는 동적 암호는 중간충돌공격과 선형 암호해독법에 대해서 안전하다. 또한 동적 암호에 대한 미분 분석이 힘든 것을 보여준다. Dynamic cipher has the property that the key-size, the number of round, and the plain text-size are scalable simultaneously. In this paper we propose the block cipher algorithm which is symmetrical in the dynamic network. We present the method for designing secure Dynamic cipher against meet-in-the-middle attack and linear crytanalysis. Also, we show that the differential cryptanalysis to Dynamic cipher is hard.

A differential cryptanalysis of Yen–Chen–Wu multimedia cryptography system

Recently, Yen et al. presented a new chaos-based cryptosystem for multimedia transmission named “multimedia cryptography system” (MCS). No cryptanalytic results have been reported so far. This paper presents a differential attack to break MCS, which requires only seven chosen plaintexts. The complexity of the attack is O ( N ) , where N is the size of plaintext. Experimental results are also given to show the real performance of the proposed attack.